Move PrivateAddressCoordinator from Tethering to staticlibs

This CL moves PrivateAddressCoordinator from Tethering to staticlibs
so that RoutingCooridnatorService can create an instance of
PrivateAddressCoordinator.

Bug: 350699020

Change-Id: I13ccd515972243719465c1c9ab844f802bc8884b
6 files changed