Directly set isKeyguardGoingAway in repo

When launching an activity from a pulsing notif while
DOZING, the launch animation can sometimes run before
the transition to GONE happens, which leaves the clock
overlapping the animation a bit.

Set the signal directly as opposed to waiting for a
callback.

Fixes: 373550549
Test: atest FromDozingTransitionInteractorTest
Flag: EXEMPT bugfix
Change-Id: I2a6f16512ef5370a480dfefcf2857403baa2af55