SystemUI: Add double tap to sleep gesture

Change-Id: I4c54718e8ec8774677d13917b3a7ffa3b4b18cb5
Signed-off-by: cj360 <ayunker551@gmail.com>

Conflicts:
	core/java/android/provider/Settings.java
SystemUI: PhoneStatusBarView: disable DEBUG_GESTURES

Change-Id: I3911c464d1f008ac2c96a1104761007fad41a3ae
Signed-off-by: Roman Birg <roman@cyngn.com>
SystemUI: double tap to sleep improvements

* Make it more reliable
* Add it to keyguard
* Add a content observer to not always query Settings.System on every
touch event

Change-Id: I292c4d9d9f810843590b7a9ec6e15b99ac44009d
Signed-off-by: Roman Birg <roman@cyngn.com>
Signed-off-by: cj360 <ayunker551@gmail.com>

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