Reapply custom lockscreen when switching to swipe mode

When switching back to swipe mode we call clearLock which resets the
password quality to unspecified.  This causes the custom lockscreen to
not show.  We reset the custom lockscreen so that the password quality
is updated accordingly.

Change-Id: I7793a110f1301a3eca8c84687e26780f0f82991a
issue-id: YAM-136
(cherry picked from commit 79c0355e)