Have PermissionMonitor arbiter which app can access background networks

This will let ConnectivityService send the right callbacks to the
relevant apps.

Test: manual with apps
      runtest frameworks-net
      cts
      new tests for this functionality
Bug: 67408339

Change-Id: I6f08efd9e73c7e191f833d7f307a3bf4c9e2f0b4
4 files changed
tree: 7eef329a6baabfbc93030590bc7848e60b4cd723
  1. core/
  2. services/
  3. tests/