Add enableCameraCompatForDesktopWindowing to devoptions.

This change allows the feature to be disabled using Developer Options. This is a common practice for Desktop Windowing (DW), which is in turn also enabled only via Developer Options. All DW sub-features are enabled when the main feature flag is enabled, and so will this feature (child CL).

Also, for developers that would like to opt-out from this camera compatibility treatment, they can see how their feature behaves without the treatment (if at all targeted). Before the public release, camera compat treatment will have an AndroidManifest property for apps to opt-out.

Flag: com.android.window.flags.enable_camera_compat_for_desktop_windowing
Test: m
Bug: 403569194
Change-Id: I45827d5a5ffe5363a95232095a47b157563c05b4