refactor: change class used for message forwarding
refactor: change class used for message forwarding

The client class should be the only one accessing the client socket, and
the device class the one accessing the device socket.

googleinterns/android-cuttlefish-halyard,googleinterns/android-cuttlefish-halyard,googleinterns/android-cuttlefish-halyard,googleinterns/android-cuttlefish-halyard