Settings: Fix possible illegal argument exception

User reported this exception during toggle settings from QS
Just check if receiver where attached before unregister them.

Change-Id: I184042bd05af28dc2ad2272fba25b650ccd2c8c1
Settings: let the controller handle all

observer should update the service.

Fix ANR for schedulService() loop on start service
	command issued

PS:
After Juba fixed the root cause and the loop the boolean check is not needed anymore

Change-Id: Ic74239fc785c3590fe8a6dd030c71cb653c43bf8
Settings: Update QuietHours Checkbox on Toggle

Register observer to listen to outside changes
	to QH state

Change-Id: I5caf9c1492e6cdd616ac58841ba1e8a6439becd1
Settings: Prevent GC from grabbing observer

Change-Id: I3c35b18550243c5e31364cac5e6ccc9ec41201ec