Firebase notification message no custom sound on Android 11 (legacy)

Question

Notification message received while the app is in background procudes no sound. It is working on Android 8 and 10 but not in 11. The test app is very simple, it just gets the Firebase token and creates a notification channel.

private void createNotificationChannel() {
    // Create the NotificationChannel, but only on API 26+ because
    // the NotificationChannel class is new and not in the support library
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        final String NOTIFICATION_ID_FCM = "notification_channel_fcm";
        
        NotificationManager notificationManager = getSystemService(NotificationManager.class);
        if (notificationManager.getNotificationChannel(NOTIFICATION_ID_FCM) != null) {
            return;
        }

        String name = "FCM Notification";
        String description = "Update FCM notification";
        int importance = NotificationManager.IMPORTANCE_DEFAULT;
        NotificationChannel channel = new NotificationChannel(NOTIFICATION_ID_FCM, name, importance);
        channel.setDescription(description);

        // Sound
        Uri notificationSoundUri =
                Uri.parse(ContentResolver.SCHEME_ANDROID_RESOURCE + "://" + BuildConfig.APPLICATION_ID + "/" + R.raw.fcm_notification);
        AudioAttributes notificationSoundUriAttributes = new AudioAttributes.Builder()
                .setUsage(AudioAttributes.USAGE_NOTIFICATION)
                .setContentType(AudioAttributes.CONTENT_TYPE_SONIFICATION)
                .build();
        channel.setSound(notificationSoundUri, notificationSoundUriAttributes);

        // Vibration. Seems a bug prevents vibration on Android 8 (api 26) in custom notification channels
        channel.enableVibration(true);
        channel.setVibrationPattern(new long[]{0, 2000});

        // Register the channel with the system; you can't change the importance
        // or other notification behaviors after this
        notificationManager.createNotificationChannel(channel);
    }
}

The JSON payload notification (from VB.Net test app using Firebase legacy api):

{
    "to": "emdoF49wRnaa0e8B7MguVK:1bGZT5Afy88jAnIviPoj_JmFCh7ScUUxcMO-jJHn1ElyPJ",
    "priority": "high",
    "notification": {
        "title": "Test 20220411 1401",
        "body": "Test body",
        "sound": "fcm_notification.wav",
        "android_channel_id": "notification_channel_fcm"
    }
}

Same result using Firebase console to send notification (even enabling sound and specifying channel notification id).

UPDATE: This happens on Samsung A10 with Android 11. Although the application appears in the settings as with sound, the notification does not emit sound. If I set the app's notification to silent...then it plays sound :( and when I go back into the notification settings it shows as with sound (although we have previously set it to silent).

Answer 1

private fun createNotificationChannel(channelId: String, channelName: String, ): String {
    val chan = NotificationChannel(channelId, channelName, NotificationManager.IMPORTANCE_HIGH)
    val sound = NotificationChannel(channelId, "Channel Sound", NotificationManager.IMPORTANCE_HIGH)
    val soundUri = Uri.parse("android.resource://" + applicationContext.packageName + "/" + R.raw.i_phone_notification)
    val audioAttributes = AudioAttributes.Builder()
        .setContentType(AudioAttributes.CONTENT_TYPE_SONIFICATION)
        .setUsage(AudioAttributes.USAGE_NOTIFICATION)
        .build()
    when (pref.getString("sound","").toString()) {
        "1" -> {
            sound.setSound(soundUri, audioAttributes)
        }
        "4" -> {
            sound.setSound( null,null)
        }
        else-> {
            sound.setSound( RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION),audioAttributes)
        }
    }
    chan.setShowBadge(true)
    chan.lightColor = Color.BLUE
    chan.lockscreenVisibility = Notification.VISIBILITY_PUBLIC
    val service = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
    service.createNotificationChannel(chan)
    service.createNotificationChannel(sound)
    return channelId
}