1593 remove iOS dependency on Firebase/Database and Firebase/Auth (cla: yes)

1597 [firebase_auth] Updated linking error code documentation (cla: yes, flutterfire)

1598 [camera] Enable camera plugin to compile with earlier android apis with custom AndroidManifest settings (cla: yes)

1600 [shared_preferences] Asynchronous commit() callback (cla: yes)

1601 Adjust user agent name (cla: yes)

1602 [webview_flutter] Fix wrong main thread checking condition. (cla: yes)

1603 Fix to check_hard_coded_version script (cla: yes)

1604 [firebase_performance] Update integration tests & version bump (cla: yes, flutterfire)

1605 [video_player] Fixed example and add texts (cla: yes)