init method Null safety

Implementation

Future<void> init() async {
  const AndroidInitializationSettings initializationSettingsAndroid =
      AndroidInitializationSettings('app_icon');

  const IOSInitializationSettings initializationSettingsIOS =
      IOSInitializationSettings(
    requestSoundPermission: true,
    requestBadgePermission: true,
    requestAlertPermission: true,
  );

  const InitializationSettings initializationSettings =
      InitializationSettings(
          android: initializationSettingsAndroid,
          iOS: initializationSettingsIOS,
          macOS: null);

  await localNotifications.initialize(initializationSettings);

  // Listen to incoming FCM payloads to handle foreground notifications.
  FirebaseMessaging.onMessage.listen((message) async {
    debugPrint("Received");
    await showMessage(message, localNotifications);
  });

  // Handles notifications in the background.
  FirebaseMessaging.onBackgroundMessage(_backgroundMessageHandler);
}