Make AQS resilient to background init in multi-process apps

[mrober]

Make AQS resilient to background init in multi-process apps. This deals with a case where a customer manually initializes Firebase in a background thread in a multi-process app. See #6599. There is a race condition and it becomes possible for AQS to access the FirebaseApp instance before Firebase has finished initializing in that process.

This just prevents the crash. A better solution would be to use Dagger for proper dependency injection instead of relying on the Firebase Components. See https://firebase.github.io/firebase-android-sdk/best_practices/dependency_injection.

[github-actions]

Release note changes

The following had changelogs that were modified, but did not have any unreleased entries for release notes to generate from.

Changelogs

firebase-sessions

[google-oss-bot]

Coverage Report ¹

Affected Products

• firebase-sessions

  Overall coverage changed from 72.61% (263fbc0) to 72.39% (46d92df) by -0.22%.

  Filename	Base (263fbc0)	Merge (46d92df)	Diff
  SessionLifecycleService.kt	81.48%	78.41%	-3.07%

Test Logs

• Base (263fbc0): https://github.com/firebase/firebase-android-sdk/actions/runs/13293626213
• Merge (46d92df): https://github.com/firebase/firebase-android-sdk/actions/runs/13295736392

1. https://storage.googleapis.com/firebase-sdk-metric-reports/1u4H9ye8z2.html

[github-actions]

Test Results

 38 files   -    996   38 suites   - 996   56s ⏱️ - 33m 49s
 95 tests  -  5 794   95 ✅  -  5 772  0 💤  - 22  0 ❌ ±0 
190 runs   - 11 651  190 ✅  - 11 607  0 💤  - 44  0 ❌ ±0 

Results for commit 59e6201. ± Comparison against base commit 263fbc0.

This pull request removes 5794 tests.

com.google.android.datatransport.cct.CctBackendFactoryTest ‑ create_returnCCTBackend_WhenBackendNameIsCCT
com.google.android.datatransport.cct.CctDestinationTest ‑ cctDestination_shouldOnlySupportProtoAndJson
com.google.android.datatransport.cct.CctDestinationTest ‑ cctDestination_shouldSupportProtoAndJson
com.google.android.datatransport.cct.CctTransportBackendTest ‑ decorate_whenOffline_shouldProperlyPopulateNetworkInfo
com.google.android.datatransport.cct.CctTransportBackendTest ‑ decorate_whenOnline_shouldProperlyPopulateNetworkInfo
com.google.android.datatransport.cct.CctTransportBackendTest ‑ schedule_shouldAddCookieOnPseudonymousIds
com.google.android.datatransport.cct.CctTransportBackendTest ‑ schedule_shouldDropCookieOnMixedPseudonymousIds
com.google.android.datatransport.cct.CctTransportBackendTest ‑ send_CompressedResponseIsUncompressed
com.google.android.datatransport.cct.CctTransportBackendTest ‑ send_whenBackendRedirectsMoreThan5Times_shouldOnlyRedirect4Times
com.google.android.datatransport.cct.CctTransportBackendTest ‑ send_whenBackendRedirects_shouldCorrectlyFollowTheRedirectViaPost
…

[google-oss-bot]

Size Report ¹

Affected Products

• firebase-sessions

  Type	Base (263fbc0)	Merge (46d92df)	Diff
  aar	168 kB	168 kB	+139 B (+0.1%)
  apk (aggressive)	559 kB	560 kB	+180 B (+0.0%)
  apk (release)	5.52 MB	5.52 MB	+168 B (+0.0%)

Test Logs

• Base (263fbc0): https://github.com/firebase/firebase-android-sdk/actions/runs/13293626213
• Merge (46d92df): https://github.com/firebase/firebase-android-sdk/actions/runs/13295736392

1. https://storage.googleapis.com/firebase-sdk-metric-reports/mhkYNYphqZ.html