+ Remove NormalProcessProxy and ProcessProxy as they are not used
anymore.
+ Rename AndroidServiceProxy to DaemonProxy and simplify its
implementation as it does not extend to ProcessProxy anymore.
+ Execute connect() in VpnService in one thread, which simplifies socket
and error handling.
+ Modify service subclasses accordingly.
+ Execute connect() and disconnect() in VpnServiceBinder so that the
operations do not block the UI thread. Mark service as foreground only upon
connecting.
21bd4af88a