SystemUI: fix custom back button image not restoring

Change-Id: I4f564662da21860ab03d10300f52b70590c0f8fc
Signed-off-by: Roman Birg <romanbirg@gmail.com>
SystemUI: fix navigation bar vibration behavior

GlowPadView was vibrating on touch, so there was
an unwanted behavior of the phone vibrating any time
the navigation bar was touched anywhere on an empty
space.

This patch disables the GlowPadView vibration, and
implements its own vibration logic.

Change-Id: Ib78ee94701e889bde9527e3c68f79b8c16623005
Signed-off-by: Roman Birg <romanbirg@gmail.com>