Active display: Add threshold to promimity sensor…
… [log]

Display will only be activated if the proximity sensor is covered for 5 seconds or more.

Change-Id: I0e9744d82884fc7aa7671ca8c93f49430359fee6

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/policy/activedisplay/ActiveDisplayView.java