Mark camera as closed before notifying listeners.

This was the behaviour when only one camera policy existed. When
`CameraStateMonitor` was extracted, listeners were notified first.
There is an issue if the config update on camera close is synchronous:
it is possible to read camera compat values as if the camera compat mode
is still active, because `CameraStateMonitor` used to still provide
camera-running signal until listeners processed onCameraClosed.

Flag: com.android.window.flags.enable_camera_compat_for_desktop_windowing
Fixes: 380292051
Test: atest WmTests:CameraStateMonitorTests
Change-Id: I2acd2f7619dfafd24c5934377679b396130623e7