Allow caller to specify target to start in setQuietModeEnabled

So, UMS can start the target once user is unlocked.

Test: No secure lock. Try turn off and on work mode by tapping work app.
Test: Have secure lock. Try turn off and on work mode by tapping work app.
Test: Turn off work mode. Reboot. Try to tap on any work app to turn on work mode.

BUG:69926710

Change-Id: Iaaccd5d763f7e36e5a43bad5261f1eb16060f9d6