When you are using Flutter and add firebase auth and Firebase Analytics to your project, you might be facing the below error in debug console:
Note: C:\src\flutter\.pub-cache\hosted\pub.dartlang.org\firebase_analytics-....\android\src\main\java\io\flutter\plugins\firebase\analytics\FlutterFirebaseAnalyticsPlugin.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details. Note: C:\src\flutter\.pub-cache\hosted\pub.dartlang.org\firebase_auth-....\android\src\main\java\io\flutter\plugins\firebase\auth\FlutterFirebaseAuthPlugin.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details.
Issue is basically seen because of dependencies versions compatibility issue into your project.
A quick way to fix the error would be to update all the dependencies to the latest version into your project and error would be fixed.