Allow non-repeating bedtime notification sound

From Fenhl on 2015/04/23 17:59:11 +0000

I have a bedtime notification set up, but unlike regular notifications its sound loops infinitely until dismissed. I would like an option to play it only once.

Copied from original feature request: http://urbandroid.uservoice.com/forums/264867-sleep-as-android/suggestions/7679334-allow-non-repeating-bedtime-notification-sound