Stop dream when keyguard dismisses for trampoline activity launches

Right now, the dream exit animations stalls in some cases and the dream
activity stays visible for ~5s after unlocking.

See bug for before/after videos, tested with/without device lock for
various widgets that use trampoline activities.

Bug: 362841648
Test: atest WidgetTrampolineInteractorTest
Flag: com.android.systemui.communal_hub
Change-Id: I062f7e1be3713f7f9d4c7b91ad9457166b62c751