QS: Add loading when toggling state, and longpress brightness

Change-Id: Ifa133e15259b45da4c625ce47b3f12209bcd1b94

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/phone/QuickSettings.java
	packages/SystemUI/src/com/android/systemui/statusbar/phone/QuickSettingsTileView.java