Trigger user activity when home panel dream unexpectedly ends

This mirrors the existing behavior of other dreams, and is used to reset
the screen timeout so we re-enter the dream again after an app update or
crash.

Fixes: 329894798
Test: atest HomeControlsComponentInteractorTest
Test: adb install home controls app repeatedly and ensure dream gets
restarted
Flag: ACONFIG android.service.controls.flags.home_panel_dream TRUNKFOOD

Change-Id: I0f2ea18dfaec347655b3d2a2a873f07ff45a1552