Get Credential Email from android smartlock

MainActivity.java

public class LoginActivity extends BaseActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ...
        ...  
        CredentialsOptions options = new CredentialsOptions.Builder().forceEnableSaveDialog().build();
        mCredentialsClient = Credentials.getClient(this, options);

        requestCredentials();
    }

    private void requestCredentials() {
        // Request all of the user's saved username/password credentials.  We are not using
        // setAccountTypes so we will not load any credentials from other Identity Providers.
        CredentialRequest request = new CredentialRequest.Builder()
                .setPasswordLoginSupported(true)
                .setIdTokenRequested(true)
                .build();

        mCredentialsClient.request(request).addOnCompleteListener(
                task -> {
                    if (task.isSuccessful()) {
                        // Successfully read the credential without any user interaction, this
                        // means there was only a single credential and the user has auto
                        // sign-in enabled.
                        processRetrievedCredential(task.getResult().getCredential());
                        return;
                    }

                    Exception e = task.getException();
                    if (e instanceof ResolvableApiException) {
                        // This is most likely the case where the user has multiple saved
                        // credentials and needs to pick one. This requires showing UI to
                        // resolve the read request.
                        ResolvableApiException rae = (ResolvableApiException) e;
                        try {
                            rae.startResolutionForResult(LoginActivity.this, Constant.SMARTLOCK_REQUEST);
                        } catch (IntentSender.SendIntentException e1) {
                            e1.printStackTrace();
                        }
                        return;
                    }
                });
    }
  
    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        switch (requestCode) {
            case Constant.SMARTLOCK_REQUEST:
                if (resultCode == RESULT_OK) {
                    Credential credential = data.getParcelableExtra(Credential.EXTRA_KEY);
                    processRetrievedCredential(credential);
                }
                break;
        }
    }

    private void processRetrievedCredential(Credential credential) {
        email.setText(credential.getId());
        password.setText(credential.getPassword());
    }
}