Unregister listeners from ClockRegistry when destroyed

We now need to keep track of ClockRegistry per lifecycleOwner or we
could risk having a ClockRegistry with already unregistered listeners
used elsewhere (eg, if the injector is called from 2 different Activities)

Fixes: 283124260
Test: manually verified going through all screens with clocks and checking no leaks
Change-Id: I1390646a1dfbf745a0c7b90dcd1c6a988ed4421d