async onTerminateApp(event) {
    Object.assign(this.context, {
      bundleId: '',
      launchArgs: null,
      pid: NaN,
      isAppReady: undefined,
    });
  }
Hook that is supposed to be called after app has been terminated

@protected
@async
@param {Object} event - App termination event object
@param {string} event.deviceId - Current deviceId
@param {string} event.bundleId - Terminated bundleId
@return {Promise<void>} - when done