Use opt-out instead of opt-in approach for camera compat.

Due to improved success rate, the feature works better when enabled
for all targeted apps (mainly fixed-orientation) and opting-out
where needed (opt-out approach), rather than opting-in apps
individually.

This opt-out override uses a new name, that matches the developer property.

The opt-in hasn't been used yet.

Flag: com.android.window.flags.enable_camera_compat_for_desktop_windowing_opt_out
Test: atest WmTests:CameraCompatFreeformPolicyTest
Test: atest WmTests:ActivityRecordTests
Test: atest WmTests:AppCompatCameraOverridesTest
Bug: 398195815
Change-Id: I9cf0b393d4157abecd5a676396415e3b4211b987