Issue #2335763: Cant dial emergency number on my device

This may fix the issue, but we have no repro steps so no way to
make sure.

What appeared to be going on was that the emergency dialer was
created, but still had the starting preview window above it.  We
were stuck in this state because the preview window didn't have
the "hide lock screen" flag set, so the lock screen would never
be removed, and thus we would never take care of finishing the
show of the emergency dialer (because it was not visible) and
thus not remove the starting window.

The solution here is to simply propagate the lock flags up to the
starting window.

Change-Id: I6da9f6494537f0661d9d230664ebf745c293ea7d