getCredentials method
Retrieves the credentials from the native storage and refresh them if they have already expired.
Uses the MethodChannel to communicate with the Native platforms.
Implementation
@override
Future<Credentials> getCredentials(
final CredentialsManagerRequest<GetCredentialsOptions> request) async {
final Map<String, dynamic> result = await _invokeMapRequest(
method: credentialsManagerGetCredentialsMethod, request: request);
return Credentials.fromMap(result);
}