Fix issue where launch transition would never end

We had the same state twice: StatusBar and KeyguardUpdateMonitor,
this led to issues because we were not finishing the transition
in KeyguardUpdateMonitor.
Now the variable doesn't exist anymore in StatusBar and we only
have one source of truth.

Fixes: 118658627
Test: press power, then double press power
Change-Id: Ia97fc7660b1cb6814c5c3fccfc8acfb0b47c3c9b