isSignedIn method
check if the user is current signed in or not.
Implementation
Future<bool> isSignedIn() {
return getSignedInUser().then((user) => user != null);
// AuthenticatedUser? user = getCurrentUser();
// if (user != null) {
// // use the Provider to check sign in status
// if (user.provider == SignInProvider.firebase) {
// if (customFirebaseApp != null) {
// return Future.value(
// FirebaseAuth.instanceFor(app: customFirebaseApp!).currentUser !=
// null);
// }
// } else if (user.provider == SignInProvider.auth0) {
// return Future.value(Auth0CredentialsManager().hasCredentials());
// }
//
// // fallback to using the client to check for status
// if (user.client == SignInClient.google) {
// return GoogleAuthManager().isSignedIn();
// } else if (user.client == SignInClient.apple) {
// // nothing to do
// } else if (user.client == SignInClient.microsoft) {
// // TODO
// }
//
// // TODO: we have the current user in memory, does that mean signed in still?
// return Future.value(true);
// }
// return Future.value(false);
}