fix(perps): open_position event should be numeric rather than boolean cp-7.61.0 (MetaMask#23557)

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## **Description**

Fixed incorrect data type for the `OPEN_POSITION` analytics property in
the Perps Market Details view. The property was incorrectly sending a
boolean value (`!!existingPosition`) instead of a numeric value, which
is inconsistent with other usages across the codebase and breaks
analytics data type expectations.


## **Changelog**

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## **Related issues**

Fixes MetaMask#23592
Slack Conversation:
https://consensys.slack.com/archives/C092T3GPHQD/p1764662917780139

## **Manual testing steps**

```gherkin
Feature: Perps Market Details Analytics

  Scenario: user views market details with existing position
    Given user has an open position in a perps market
    
    When user navigates to the market details view
    Then the OPEN_POSITION analytics property should be sent as number 1

  Scenario: user views market details without existing position
    Given user has no open position in a perps market
    
    When user navigates to the market details view
    Then the OPEN_POSITION analytics property should be sent as number 0
```

## **Screenshots/Recordings**

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### **Before**

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### **After**

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## **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
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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]
> Change OPEN_POSITION analytics property to 1/0 instead of boolean in
Perps Market Details screen event.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
8ff0f75. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: gambinish

app/components/UI/Perps/Views/PerpsMarketDetailsView/PerpsMarketDetailsView.tsx

@@ -435,7 +435,7 @@ const PerpsMarketDetailsView: React.FC<PerpsMarketDetailsViewProps> = () => {
       [PerpsEventProperties.ASSET]: market?.symbol || '',
       [PerpsEventProperties.SOURCE]:
         source || PerpsEventValues.SOURCE.PERP_MARKETS,
-      [PerpsEventProperties.OPEN_POSITION]: !!existingPosition,
+      [PerpsEventProperties.OPEN_POSITION]: existingPosition ? 1 : 0,
       // A/B Test context (TAT-1937) - for baseline exposure tracking
       ...(isButtonColorTestEnabled && {
         [PerpsEventProperties.AB_TEST_BUTTON_COLOR]: buttonColorVariant,