Use activity from the same task when closing the camera.

The main goal of the change is to use the same way of choosing activities as the CameraCompatFreeformPolicy,
so that common control logic could be extracted eventually. While testing manually with switching apps,
 I haven't noticed a change in behavior.

Flag: com.android.window.flags.camera_compat_fullscreen_pick_same_task_activity
Bug: 350495350
Test: atest WmTests:DisplayRotationCompatPolicyTests
Change-Id: I536a05e969c8c9d1d8032b7b6d193725c7ee4654