Fix 3061025: Extend wave lockscreen timeout while grabbed.

This fix extends the lockscreen timeout to 30s while the
handle is being held.  As a precaution, it will still timeout
after 30s of not completing the lock. Once the handle is
released, the screen will go dark after 5s, which gives
it enough time to finish pending animations.

Change-Id: Ie89449b6b09de06ca8a88702cc85085b2556903c