[NS08] Expose public NetworkScore API

This exposes the two bits settable by the network agents in
Android S on NetworkScore. This is meant to be extensible in
future releases, or possibly for OEM upstreams.

Test: builds
CTS-Coverage-Bug: 184037351
Bug: 167544279
Merged-In: I3c2563d4ae4e3715d0c6270344ba8f7ef067872f
Merged-In: Id7ee1bd3e2679f0bd5200d5c299f18a33b87847c
Change-Id: Id7ee1bd3e2679f0bd5200d5c299f18a33b87847c
  (cherry-picked from ag/14010221)
2 files changed