Revert "Active display: unregister proximity if pocket mode not used or active display disabled"

This reverts commit 8815f8f74e9950f06391355beac910872b4013f1.
Active display: make sure mNotificaiton is set correctly

Change-Id: I4111ca843e340cca4d6dac4b2c2922ce3039e487

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/policy/activedisplay/ActiveDisplayView.java
Active display: register/unregister recievers and listeners when enabled/disabled

Change-Id: Ic73e63da2c9634bc864ab1a1387eb9145eb0b5b0

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

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/policy/activedisplay/ActiveDisplayView.java
Active Display: check if recievers and listeners are registered

Change-Id: I1a881aebcbfc2bae92535a4e9ea55ba3789d8b43