Use callbacks instead of broadcasts to update LOHS state

Besides switching to callbacks, this improves the handling of errors.
For devices that can support both tethered softap and local-only hotspot
at the same time, this means that a teardown of one no longer means
a teardown of the other.

Bug: 71714381
Test: atest WifiServiceImplTest
Change-Id: Ia740b114a87dfd433332c26aed96fca48141829f
4 files changed
tree: 3a338def3165b10d52d840c101a0988eca68562d
  1. service/
  2. PREUPLOAD.cfg