revert: remove feature-flags to user traits tracking (PR MetaMask#24178) (MetaMask#24317)

<!--
Please submit this PR as a draft initially.
Do not mark it as "Ready for review" until the template has been
completely filled out, and PR status checks have passed at least once.
-->

## **Description**

This reverts the changes from PR MetaMask#24178 that added automatic tracking of
remote feature flags to user traits via addTraitsToUser.
Automatic Github revert not available for this PR.

Reverted changes:
- Removed useEffect hook that called addTraitsToUser with
rawFeatureFlags
- Removed useMetrics import and addTraitsToUser usage
- Removed related unit tests for feature flag user traits tracking

## Related

Reverts MetaMask#24178

## **Changelog**

<!--
If this PR is not End-User-Facing and should not show up in the
CHANGELOG, you can choose to either:
1. Write `CHANGELOG entry: null`
2. Label with `no-changelog`

If this PR is End-User-Facing, please write a short User-Facing
description in the past tense like:
`CHANGELOG entry: Added a new tab for users to see their NFTs`
`CHANGELOG entry: Fixed a bug that was causing some NFTs to flicker`

(This helps the Release Engineer do their job more quickly and
accurately)
-->

CHANGELOG entry: null

## **Related issues**

Reverts MetaMask#24178

## **Manual testing steps**

Identify calls should be sent to Segment server again.

## **Screenshots/Recordings**

NA

### **Before**

NA

### **After**

NA

## **Pre-merge author checklist**

- [x] I’ve followed [MetaMask Contributor
Docs](https://github.com/MetaMask/contributor-docs) and [MetaMask Mobile
Coding
Standards](https://github.com/MetaMask/metamask-mobile/blob/main/.github/guidelines/CODING_GUIDELINES.md).
- [x] I've completed the PR template to the best of my ability
- [x] I’ve included tests if applicable
- [x] I’ve documented my code using [JSDoc](https://jsdoc.app/) format
if applicable
- [x] I’ve applied the right labels on the PR (see [labeling
guidelines](https://github.com/MetaMask/metamask-mobile/blob/main/.github/guidelines/LABELING_GUIDELINES.md)).
Not required for external contributors.

## **Pre-merge reviewer checklist**

- [ ] I've manually tested the PR (e.g. pull and build branch, run the
app, test code being changed).
- [ ] I confirm that this PR addresses all acceptance criteria described
in the ticket it closes and includes the necessary testing evidence such
as recordings and or screenshots.


<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> Reverts automatic syncing of remote feature flags to user traits.
> 
> - Removes `useMetrics` import and the `useEffect` that called
`addTraitsToUser(rawFeatureFlags)` in `FeatureFlagOverrideContext.tsx`
> - Deletes related unit tests and mocks in
`FeatureFlagOverrideContext.test.tsx` for bulk/add-on-change trait
updates
> - Keeps feature flag override functionality (set/remove/clear) intact
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
27ec9cd. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

---------

Co-authored-by: Cursor Agent <cursoragent@cursor.com>

Author: NicolasMassart

app/contexts/FeatureFlagOverrideContext.test.tsx

@@ -1,11 +1,5 @@
 import React from 'react';
-import {
-  renderHook,
-  act,
-  render,
-  screen,
-  waitFor,
-} from '@testing-library/react-native';
+import { renderHook, act, render, screen } from '@testing-library/react-native';
 import { useSelector } from 'react-redux';
 import { Text } from 'react-native';
 import {
@@ -54,15 +48,6 @@ jest.mock('../util/feature-flags', () => ({
   getFeatureFlagType: jest.fn(),
 }));
 
-// Mock useMetrics hook
-const mockAddTraitsToUser = jest.fn();
-jest.mock('../components/hooks/useMetrics/useMetrics', () => ({
-  __esModule: true,
-  default: jest.fn(() => ({
-    addTraitsToUser: mockAddTraitsToUser,
-  })),
-}));
-
 describe('FeatureFlagOverrideContext', () => {
   let mockUseSelector: jest.MockedFunction<typeof useSelector>;
   let mockGetFeatureFlagType: jest.MockedFunction<typeof getFeatureFlagType>;
@@ -72,7 +57,6 @@ describe('FeatureFlagOverrideContext', () => {
 
   beforeEach(() => {
     jest.clearAllMocks();
-    mockAddTraitsToUser.mockClear();
     mockSetFlagOverride.mockClear();
     mockRemoveFlagOverride.mockClear();
     mockClearAllFlagOverrides.mockClear();
@@ -729,102 +713,4 @@ describe('FeatureFlagOverrideContext', () => {
       expect(result.current.hasOverride('')).toBe(true);
     });
   });
-
-  describe('Remote Feature Flag Change Tracking', () => {
-    it('adds all feature flags to user traits in bulk when received', async () => {
-      const mockFlags = {
-        booleanFlag: true,
-        stringFlag: 'variant_a',
-        numberFlag: 42,
-      };
-      mockUseSelector.mockReturnValue(mockFlags);
-
-      renderHook(() => useFeatureFlagOverride(), {
-        wrapper: createWrapper,
-      });
-
-      await waitFor(() => {
-        expect(mockAddTraitsToUser).toHaveBeenCalledWith({
-          booleanFlag: true,
-          stringFlag: 'variant_a',
-          numberFlag: 42,
-        });
-      });
-    });
-
-    it('adds all feature flags to user traits in bulk when flags change', async () => {
-      const initialFlags = { flag1: true, flag2: 'variant_a' };
-      mockUseSelector.mockReturnValue(initialFlags);
-
-      const { rerender } = renderHook(() => useFeatureFlagOverride(), {
-        wrapper: createWrapper,
-      });
-
-      mockAddTraitsToUser.mockClear();
-
-      const updatedFlags = { flag1: false, flag2: 'variant_b', newFlag: 100 };
-      mockUseSelector.mockReturnValue(updatedFlags);
-
-      rerender(null);
-
-      await waitFor(() => {
-        expect(mockAddTraitsToUser).toHaveBeenCalledWith({
-          flag1: false,
-          flag2: 'variant_b',
-          newFlag: 100,
-        });
-      });
-    });
-
-    it('does not call addTraitsToUser when no feature flags exist', async () => {
-      mockUseSelector.mockReturnValue({});
-
-      renderHook(() => useFeatureFlagOverride(), {
-        wrapper: createWrapper,
-      });
-
-      await waitFor(
-        () => {
-          expect(mockAddTraitsToUser).not.toHaveBeenCalled();
-        },
-        { timeout: 200 },
-      );
-    });
-
-    it('sends user traits in a single bulk call, not per-flag', async () => {
-      const mockFlags = { flag1: true, flag2: 'variant', flag3: 123 };
-      mockUseSelector.mockReturnValue(mockFlags);
-
-      renderHook(() => useFeatureFlagOverride(), {
-        wrapper: createWrapper,
-      });
-
-      await waitFor(() => {
-        // Should be called exactly once with all flags
-        expect(mockAddTraitsToUser).toHaveBeenCalledTimes(1);
-        expect(mockAddTraitsToUser).toHaveBeenCalledWith({
-          flag1: true,
-          flag2: 'variant',
-          flag3: 123,
-        });
-      });
-    });
-  });
-
-  describe('Bulk Traits on Mount', () => {
-    it('calls addTraitsToUser in bulk on mount with all feature flags', () => {
-      const mockFlags = { stringFlag: 'test', boolFlag: true };
-      mockUseSelector.mockReturnValue(mockFlags);
-
-      renderHook(() => useFeatureFlagOverride(), {
-        wrapper: createWrapper,
-      });
-
-      // useEffect sends all flags in bulk on mount
-      expect(mockAddTraitsToUser).toHaveBeenCalledWith({
-        stringFlag: 'test',
-        boolFlag: true,
-      });
-    });
-  });
 });

app/contexts/FeatureFlagOverrideContext.tsx

@@ -4,7 +4,6 @@ import React, {
   useCallback,
   ReactNode,
   useMemo,
-  useEffect,
 } from 'react';
 import { useSelector } from 'react-redux';
 import {
@@ -13,7 +12,6 @@ import {
   selectRawFeatureFlags,
 } from '../selectors/featureFlagController';
 import { FeatureFlagInfo, getFeatureFlagType } from '../util/feature-flags';
-import useMetrics from '../components/hooks/useMetrics/useMetrics';
 import Engine from '../core/Engine';
 import type { Json } from '@metamask/utils';
 
@@ -44,21 +42,13 @@ interface FeatureFlagOverrideProviderProps {
 export const FeatureFlagOverrideProvider: React.FC<
   FeatureFlagOverrideProviderProps
 > = ({ children }) => {
-  const { addTraitsToUser } = useMetrics();
   // Get the initial feature flags from Redux
   const featureFlagsWithOverrides = useSelector(selectRemoteFeatureFlags);
   const rawFeatureFlags = useSelector(selectRawFeatureFlags);
 
   // Get overrides from controller state via Redux
   const overrides = useSelector(selectLocalOverrides);
 
-  // Track remote feature flags and add all flags to user traits in bulk
-  useEffect(() => {
-    if (rawFeatureFlags && Object.keys(rawFeatureFlags).length > 0) {
-      addTraitsToUser(rawFeatureFlags);
-    }
-  }, [rawFeatureFlags, addTraitsToUser]);
-
   const setOverride = useCallback((key: string, value: unknown) => {
     Engine.context?.RemoteFeatureFlagController?.setFlagOverride(
       key,