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

Give user ability to hide error pattern / dots.

Patchset 2 : Cleanup commit msg

Change-Id: Ifdd4615c7116f974a0a67079d58a521e84d76367
PIE: slightly smaller as default

Change-Id: I307749f1e894e8e31a7b0b8bc39a0da11c20090f