Enable "Reboot to safe mode" confirmation on GlobalActions

Android N or prior GlobalActions showed "Reboot to safe mode",
when user do long-press of "power off" button on GlobalActions.

Currently, no confirmation dialog is shown. It's not user friendly.
This commit make it enable again.

 - Also dismiss global actions on long press.

Test: manual
Bug: 37333890
Change-Id: I3bfefff3cd34ba35b003281e94a4181cebb74fcf