delete method
clear password for an id
id: ID String, this cannot be empty throws ArgumentError: id is empty
Web: Overwrite Credential with Empty Password Android: Delete Credential
Implementation
Future<void> delete(String id) async {
  if (id.isEmpty) {
    throw ArgumentError.value(id, "id cannot be empty");
  }
  return await _channel.invokeMethod("delete", <String, dynamic>{"id": id});
}