Merge changes Ic4742bf5,I2c8a8e7f,I755a9a55,I2148bce6

* changes:
  NetworkProvider: improve documentation of unregisterNetworkOffer
  Revert "NetworkProvider: Do not propagate callbacks for unregistered offers"
  DscpPolicy: match_policy is_eth is always true
  DscpPolicy: remove bpf support for raw ip