Option to send a Test Notification

Quite a few People seem to be having Issues with properly receiving Notifications when using UnifiedPush with the OSS version of the Android Beta.

It would be nice having an option in the notification settings to send a test notification in order to better and more conveniently be able to identify issues.

• This would be a good option to point people to when they ask for help
• The Option should propably have a cooldown to avoid spam
• There should be a text feedback below the button if the request was received (or the result should be logged in the app logs)