LockscreenPattern : Toggle dots/error pattern visibility (2/2)

Give user ability to hide error pattern / dots.

Patchset 2 : Cleanup commit msg

Change-Id: Ifdd4615c7116f974a0a67079d58a521e84d76367
Hide Superuser entry if root access for apps is disabled.

Change-Id: Ibb77ba5a0fccf22564a26b8b1e13f7762c65718e