Controls Activity - Always close when keyguard becomes active

The ControlsActivity can be launched over lockscreen when the user
permits, or only while unlocked. However, leaving the occluded
activity up while the screen is off can lead to potential issues, as
well as just being against user expectations for the activity.

Fixes: 197391802
Test: manual, launch device controls and power the screen off

Change-Id: I50a4d17a24c0d73f320f2637488f7ae502dddae9