getGoogleYoloClientId() {
    const signInOptions = this.getSignInOptionsForProvider_(
        firebase.auth.GoogleAuthProvider.PROVIDER_ID);
    if (signInOptions &&
        signInOptions['clientId'] &&
        this.getCredentialHelper() === Config.CredentialHelper.GOOGLE_YOLO) {
      return signInOptions['clientId'] || null;
    }
    return null;
  }
@return {?string} The googleyolo configuration client ID if available.