DeviceKeyHandler : Allow handling keyevents while screen off

Some devices require the keyevents to be processed while the screen
is off, this patchset addresses that by moving the filter up in the call
hierarchy.

Change-Id: If71beecc81aa5e453dcd08aba72b7bea5c210590
Correct padding for status bar icons

4dp is used in AOSP.

Change-Id: I7f97cb9feabe267c67722d600d0891ab2ce1a907