isAccountSelectionPromptEnabled() {
    // This is only applicable to Google. If prompt is set, googleyolo retrieve
    // is disabled. Auto sign-in should be manually disabled.
    // Get Google custom parameters.
    const googleCustomParameters = this.getProviderCustomParameters(
        firebase.auth.GoogleAuthProvider.PROVIDER_ID);
    // Google custom parameters must have prompt set to select_account,
    // otherwise account selection prompt is considered disabled.
    return !!(googleCustomParameters &&
              googleCustomParameters['prompt'] === 'select_account');
  }
@return {boolean} Whether the user should be prompted to select an
    account.