SystemUI: Add double tap to sleep gesture

 Change-Id: I4c54718e8ec8774677d13917b3a7ffa3b4b18cb5

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

Change-Id: Idcf0d72736e3302a57a91649d51009103f7b0538