Prevent NPE in ControlsListingControllerImpl

Move initialization of callbacks list to before the ServiceListing is
reloaded. That way, it will always be initialized by the time the
listener is called.

Fixes: 153448765
Test: atest ControlsListingControllerImpl
Change-Id: I67ba7f3d4bd74f38d0e6f69857135864dcf4a573