Merge changes from topics "pans", "pans-permission"

* changes:
  Marking setOemNetworkPreference as @SystemApi
  Adding permission for OEM managed preferences
  Implementation of setOemNetworkPreference
tree: 62fba769b57609ab3dd97c6096ef5912bd2fde6c
  1. core/
  2. framework/
  3. service/
  4. services/
  5. tests/
  6. OWNERS