[TIMOB-25591] Android: Programmatically check whether app has notification permission on Android

In Android settings, users can turn off notification if they don't want to. So need a method that like areNotificationsEnabled() to check if my app is allowed to show a notification. Then need to open android setting page to guide users to turn on the notification. It's available since 24.1.0 on native Android https://developer.android.com/reference/android/support/v4/app/NotificationManagerCompat.html#areNotificationsEnabled()