main function Null safety

Implementation

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  MobileAds.instance.initialize();

  RequestConfiguration configuration = RequestConfiguration(testDeviceIds: testDeviceIds);
  MobileAds.instance.updateRequestConfiguration(configuration);

  await Firebase.initializeApp(
    options: DefaultFirebaseOptions.currentPlatform,
  );
  runApp(const MyApp());
}