InAppUpdateListener.kt

 private val listener: InstallStateUpdatedListener? = InstallStateUpdatedListener { installState ->
        if (installState.installStatus() == InstallStatus.DOWNLOADED) {
            // After the update is downloaded, show a notification
            // and request user confirmation to restart the app.
            Log.d(TAG, "An update has been downloaded")
                showSnackBarForCompleteUpdate()
        }
    }