Fix activity cannot goes to stop when keyguard shown.

1. Fix activity shows on non-default display cannot goes to STOPPED
successfully when keyguard shown. Previous when keyguard shows,
there is only one sleep token for default display, for those
activity runs on non-default display, they cannot go to STOPPED
because they cannot be removed from
StackSupervisor.mActivitiesWaitingForVisibleActivity, which cause
them be stuck at RESUMED state.
2. Providing a basic struct for KeyguardController to handle occludes
and dismiss keyguard for each display.

Bug: 112823693
Test: atest CtsActivityManagerDeviceTestCases
Change-Id: I9c2de47e65bbb7a193f0b00246f3c13db7f6b3b5