Fix 2679658: Be more aggressive about recreating lock screen.

In the past we were overly cautious about not recreating the lockscreen
under steady state conditions.  However, that allowed lockscreen
to get into weird states where the screen orientation and the
loaded layout disagree. Once in this state, the user could not
recover because we would never reload the layout due to the fixed
orientation of lock screen.

This avoids the problem by being more aggressive about reloading
the layout.  It now recreates the lockscreen (for reals) whenever
a view requests it via recreateMe().

In addition it serializes recreateMe() requests to ensure a pending
configuration change event has a chance to propagate and be handled
by the lockscreen looper.

Change-Id: I86a54abba899eb314f7cc8dbf6cbb98266bc548a