Fix Dart 2 type error and deprecation (#425)
Fix Dart 2 type error and deprecation (#425)


firebase/flutterfire,firebase/flutterfire,googleads/googleads-mobile-flutter,firebase/flutterfire,firebase/flutterfire,firebase/flutterfire,googleads/googleads-mobile-flutter,googleads/googleads-mobile-flutter,firebase/flutterfire,googleads/googleads-mobile-flutter,firebase/flutterfire,firebase/flutterfire,firebase/flutterfire,firebase/flutterfire