Add transition layer between blueprints.

Invoke TransitionManager#beginDelayedTransition with our own transition.
The default transition, AutoTransition, does not work well with our
current clock because of its canvas caching and the Fade animation that
aniamtes the transition alpha. Directly animating the alpha seems to
work better.

Bug: 288464062
Test: switch between blueprints
Change-Id: If4e244d7558eb1b558d94b375ff7e7f453288d29