getToken method Null safety

Implementation

Future<void> getToken() async {
  LogManager().addLog("getToken()", screen: runtimeType.toString());
  String? token = await FirebaseMessaging.instance.getToken();
  LogManager().addLog("token: $token", screen: runtimeType.toString());
  String? apnsToken = await FirebaseMessaging.instance.getAPNSToken();
  LogManager().addLog("apnstoken: $apnsToken", screen: runtimeType.toString());
}