Allow "Changing snooze time" toggle to be set per alarm

From Dakota E. Welsh on 2017/09/08 05:03:25 +0000

I would like to be able to change the snooze time when the alarm goes off while taking a nap, but not when I wake up in the morning. It would be nice to be able to be able to toggle the “Changing snooze time” setting in the settings for individual alarms.
Thanks!

Copied from original feature request: http://urbandroid.uservoice.com/forums/264867-sleep-as-android/suggestions/31290754-allow-changing-snooze-time-toggle-to-be-set-per