Simplify the camera compat state.

Due to previously integrating camera-compat-triggered recalculations in
`cameraActivity.recomputeConfiguration()`, there is no need to track the
camera compat state: it can always be calculated and up-to-date.

Flag: com.android.window.flags.enable_camera_compat_for_desktop_windowing
Fixes: 347864073
Test: atest WmTests:CameraCompatFreeformPolicyTests
Test: atest WmTests:AppCompatCameraOverridesTest
Change-Id: I2074fdd473ad73c22bd807a6f7cc8e573b0c3bd0