Do not adjust camera compat treatment for activity after closing camera.

The reasoning is two-fold:
- If the activity has closed the camera but still alive, there is a good chance that the activity is showing the captured image, which could benefit from similar treatment (letterbox to a size of the camera feed, etc).
- If the camera has been closed due to closing the activity (back button/gesture) or the task (closing the window), the activity below (if any) will not have camera-related letterbox. We still want to update other parameters though, like camera params for the future use, and any TBD sandboxing done because of this treatment (that are not activity-specific).'

Removed a few tests that do not make sense anymore.

Flag: com.android.window.flags.camera_compat_for_freeform
Test: atest WmTests:CameraCompatFreeformPolicyTests
Fixes: 347882285
Change-Id: I3a7a95b168700674fac3c9538fdd218c46ccfac2