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

This reverts commit 888baa8f349b545b7ec3edb0e5fbee80eafc71ad.
Active display: register/unregister recievers and listeners when enabled/disabled

Change-Id: Ic73e63da2c9634bc864ab1a1387eb9145eb0b5b0
Active Display: check if recievers and listeners are registered

Change-Id: I1a881aebcbfc2bae92535a4e9ea55ba3789d8b43
Active display: Catch Resources.NotFoundException

This caused the SystemUI to FC when the device was powered and a notification was fired.
Display stayed off and the SystemUI kept restarting until the device was unlocked manually.

Change-Id: Ibfd82242e82aa9ee5c0898f5f0714e490eac0ea9