Hold wake lock while animations to bold clock.

In the bug, it appears that the phone dozed during the transition.
Holding the wake lock will keep the phone awake until the transition
ends. This is a speculative change because I wasn't able to reproduce
the issue.

Bug: 135458132
Test: checked that the transition still works, but I wasn't able to
verify the fix because I'm not able to reproduce the issue.

Change-Id: Ibfd4ae7522c30882051a41927c1714ace3f08b89