Add Auth Tab Switch Browser feature flag and telemetry constants to common4j, Fixes AB#3561423 (#3072)

Adds the feature flag and attribute constants needed to instrument the
Auth Tab switch browser feature.

## Changes

### `CommonFlight.java`
- New flight:
`ENABLE_AUTH_TAB_FOR_SWITCH_BROWSER("EnableAuthTabForSwitchBrowser",
false)`

### `AttributeName.java`
Four new attributes adjacent to existing switch browser attributes:

| Constant | Type | Description |
|---|---|---|
| `auth_tab_used` | boolean | Whether Auth Tab was used |
| `auth_tab_result_code` | integer | Android Activity result code from
Auth Tab |
| `is_auth_tab_supported` | boolean | Whether Auth Tab is supported |
| `auth_tab_fallback_to_custom_tabs` | boolean | Whether Auth Tab fell
back to Custom Tabs |

> **Note:** Per `AttributeName.java` policy, the four new attribute
constants must also be mirrored in the Broker repo's
(`AzureAD/ad-accounts-for-android`) `AttributeName.java`.

Auth Tab telemetry attributes will be recorded on the existing
`SwitchBrowserProcess` span via span context propagation, rather than a
dedicated new span.

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<!-- START COPILOT ORIGINAL PROMPT -->



<details>

<summary>Original prompt</summary>

> ## Objective
> Add the feature flag enum entry and telemetry constants (attribute
names + span name) in the `common4j` module to support the Auth Tab
switch browser feature.
> 
> ## Target Repository
> - Repo: AzureAD/microsoft-authentication-library-common-for-android
> - Base Branch: dev
> - Module: common4j
> 
> ## Technical Requirements
> 
> 1. **CommonFlight.java** — Add enum entry:
> `ENABLE_AUTH_TAB_FOR_SWITCH_BROWSER("EnableAuthTabForSwitchBrowser",
false),`
>    Follow existing pattern. Default value `false`.
> 
> 2. **AttributeName.java** — Add 4 new enum constants:
>    `auth_tab_used,`
>    `auth_tab_result_code,`
>    `is_auth_tab_supported,`
>    `auth_tab_fallback_to_custom_tabs,`
> 
> 3. **SpanName.java** — Add 1 new enum constant near existing Switch
Browser entries:
>    `SwitchBrowserAuthTab,`
> 
> ## Files to Modify
> -
`common4j/src/main/com/microsoft/identity/common/java/flighting/CommonFlight.java`
> -
`common4j/src/main/com/microsoft/identity/common/java/opentelemetry/AttributeName.java`
> -
`common4j/src/main/com/microsoft/identity/common/java/opentelemetry/SpanName.java`
> 
> ## Acceptance Criteria
> - `CommonFlight.ENABLE_AUTH_TAB_FOR_SWITCH_BROWSER` exists with key
`"EnableAuthTabForSwitchBrowser"` and default `false`
> - `AttributeName` contains: `auth_tab_used`, `auth_tab_result_code`,
`is_auth_tab_supported`, `auth_tab_fallback_to_custom_tabs`
> - `SpanName` contains: `SwitchBrowserAuthTab`
> - Compile check passes
> 
> Fixes
[AB#3561423](https://identitydivision.visualstudio.com/fac9d424-53d2-45c0-91b5-ef6ba7a6bf26/_workitems/edit/3561423)
> Follow .github/copilot-instructions.md strictly
> 


</details>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: p3dr0rv <76129899+p3dr0rv@users.noreply.github.com>
Co-authored-by: p3dr0rv <pedroro@microsoft.com>

Author: Copilot

common4j/src/main/com/microsoft/identity/common/java/flighting/CommonFlight.java

@@ -262,6 +262,11 @@ public enum CommonFlight implements IFlightConfig {
      */
     ENABLE_SERVER_CLIENT_DATA_TELEMETRY("EnableServerClientDataTelemetry", true),
 
+    /**
+     * Flight to enable Auth Tab for the switch browser feature.
+     */
+    ENABLE_AUTH_TAB_FOR_SWITCH_BROWSER("EnableAuthTabForSwitchBrowser", false),
+    
     /**
      * Flight to enable filter-then-clone optimization in SharedPreferencesAccountCredentialCacheWithMemoryCache.
      * When enabled, getCredentialsFilteredBy()/getAccountsFilteredBy() filters on in-memory

common4j/src/main/com/microsoft/identity/common/java/opentelemetry/AttributeName.java

@@ -405,6 +405,26 @@ public enum AttributeName {
      */
     is_switch_browser_resume_handled,
 
+    /**
+     * Records if the Auth Tab was used in the switch browser flow (boolean).
+     */
+    auth_tab_used,
+
+    /**
+     * Records the Android Activity result code returned by the Auth Tab in the switch browser flow (integer).
+     */
+    auth_tab_result_code,
+
+    /**
+     * Records if Auth Tab is supported for the switch browser flow (boolean).
+     */
+    is_auth_tab_supported,
+
+    /**
+     * Records if the Auth Tab fell back to custom tabs in the switch browser flow (boolean).
+     */
+    auth_tab_fallback_to_custom_tabs,
+
     /**
      * The tenant id for the home tenant of the account for which PRT is required.
      */