Reset message area.

Reset message area when reset is called. Remove scrimmed code path and
merge it in with the regular path. I checked the scrimmed states on all
of the security methods and it looks good.

Fixes: 266801486
Test: added a unit test.
Test: test scrimmed bouncers for all three security methods by long
pressing the lock icon.
Test: add face unlock and get a swipe and try again message and back out
and go back to boucner.

Change-Id: I61e77d4f657db665170f0a6a32793edc50ca13f2