Make getCameraIdListNoLazy handle no service case

If we have sCameraServiceDisabled, we know for sure that calling
addListener on the mCameraService is going to fail with NPE, so the best
option is to just return an empty list.

Fix: 146994502
Test: atest android.camera.cts.HeifWriterTest
Change-Id: Ie3a1457fbace0879a5d66600acd83541a9d78182