Version 6.16.0
### 6.16.0:
- Changes
- General: Prevent Firebase SDK from causing GC in every frame.
- General (Editor): Improved the performance of Firebase Editor tools by
delay initializatoin when condition met and improve asset searching.
- General: Deprecate Firebase.Unity.Editor.FirebaseEditorExtensions. Most of
the functions is noop now and will be removed soon.
- General: **Breaking Change** Remove deprecated functions
`FirebaseApp.SetEditorAuthUserId()` and
`FirebaseApp.GetEditorAuthUserId()` in order to improve performance.
- General: (Android) Fixed that FirebaseApp failed to create for builds
created by Unity 2020+ due to google-services.json not found. All Firebase
Android resource files are moved to directories with `androidlib`
extension.
- General: (Android) Remove android:minSdkVersion from AndroidManifest.xml
under `Assets/Plugins/Android/Firebase` which is causing build error in
Unity 2020.
- Database (Desktop): Enabled offline persistence.
- Firestore: Fixed FirebaseFirestore.LogLevel for some log levels.
- Firestore: Added `Error.None` as a synonym for `Error.Ok`, which is more
consistent with other Firebase Unity APIs.
- auth.SWIG: Fix typo (across).
- Firestore: Fixed leaked memory in FirebaseFirestore C# objects.
- Crashlytics: Fixed an issue on iOS where the Crashlytics Run Script would fail to get added on versions of Unity 2018 and below [#5569](https://github.com/firebase/firebase-ios-sdk/issues/5569)
- Crashlytics: (Android) Fixed crashes for builds created by Unity 2020+ due
to build ID is missing. Generated Crashlytics Android resource files are
moved to `Plugins/Android/FirebaseCrashlytics.androidlib`.
- Firestore: Fixed `CollectionReference.AddAsync()` to propagate errors.
- Firestore: Changed async tasks to fault with `FirestoreException`.
- Firestore: Renamed the `Error` enum to `FirestoreError`.
- Messaging (Android): Updated library to be compatible with Android O,
which should resolve a IllegalStateException that could occur under
certain conditions.
- Messaging: Deprecated the `Send` function.
- Firestore: Added meaningful error messages to the exceptions with which
`ListenerRegistration.ListenerTask` tasks fault.