Introduce StayAwakePreferenceController

 - Create new StayAwakePreferenceController
 - Create controller inside the DashboardFragment
 - Port logic from DevelopmentSettings into the controller

Bug: 34203528
Test: make RunSettingsRoboTests -j40
ROBOTEST_FILTER=StayAwakePreferenceControllerTest

Change-Id: I7642656fb2e323878face52f0a3c57fec1d85ac4
3 files changed