[android] Vibrate and Sound defaults on notification

To support SDK version >= 26, you also should build NotificationChanel and set a vibration pattern and sound there. There is a Kotlin code sample:

    val vibrationPattern = longArrayOf(500)
    val soundUri = "<your sound uri>"

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            val notificationManager =    
                 getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
            val attr = AudioAttributes.Builder()
                        .setUsage(AudioAttributes.USAGE_ALARM)
                        .setContentType(AudioAttributes.CONTENT_TYPE_SONIFICATION)
                        .build()
            val channelName: CharSequence = Constants.NOTIFICATION_CHANNEL_NAME
            val importance = NotificationManager.IMPORTANCE_HIGH
            val notificationChannel =
                NotificationChannel(Constants.NOTIFICATION_CHANNEL_ID, channelName, importance)
                notificationChannel.enableLights(true)
                notificationChannel.lightColor = Color.RED
                notificationChannel.enableVibration(true)
                notificationChannel.setSound(soundUri, attr)
                notificationChannel.vibrationPattern = vibrationPattern
                notificationManager.createNotificationChannel(notificationChannel)
    }

And this is the builder:

 with(NotificationCompat.Builder(applicationContext, Constants.NOTIFICATION_CHANNEL_ID)) {
        setContentTitle("Some title")
        setContentText("Some content")
        setSmallIcon(R.drawable.ic_logo)
        setAutoCancel(true)    
        setVibrate(vibrationPattern)
        setSound(soundUri)
        setDefaults(Notification.DEFAULT_VIBRATE)
        setContentIntent(
            // this is an extension function of context you should build
            // your own pending intent and place it here
            createNotificationPendingIntent(
                Intent(applicationContext, target).apply {
                    flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK
                }
            )
        )

        return build()
    }

Be sure your AudioAttributes are chosen right to read more here.