InAppUpdate.kt

 private fun checkUpdate() {
        // Returns an intent object that you use to check for an update.
        val appUpdateInfoTask = appUpdateManager?.appUpdateInfo
        // Checks that the platform will allow the specified type of update.
        Log.d(TAG, "Checking for updates")
        appUpdateInfoTask?.addOnSuccessListener { appUpdateInfo ->
            if (appUpdateInfo.updateAvailability() == UpdateAvailability.UPDATE_AVAILABLE
                    && appUpdateInfo.isUpdateTypeAllowed(AppUpdateType.FLEXIBLE)) {
                // Request the update.
                Log.d(TAG, "Update available")
            } else {
                Log.d(TAG, "No Update available")
            }
        }
    }