Settings: Add stay awake timeout in Quick Settings and Display Settings (2/2)

Thanks to SlimRoms for the idea

Change-Id: Ibde853fb883fa50bac8457feb7e309a5608bbd29
Settings: Better description when stay awake is selected
Change-Id: I9a0e4c3276ca2ebe87232d9f208e1a4d366261ed
Settings: Better management of long press screen timeout tile to stay awake (2/2)

Change-Id: I6df3ebfd76ac2a6dfac838681af6d09e6def0f58