updatePassword method
Updates the user's password.
Important: this is a security sensitive operation that requires the user to have recently signed in. If this requirement isn't met, ask the user to authenticate again and then call User.reauthenticateWithCredential.
A FirebaseAuthException maybe thrown with the following error code:
Implementation
Future<void> updatePassword(String newPassword) async {
throw UnimplementedError('updatePassword() is not implemented');
}