ConnectivityService: Fix device hostname omission

Whoever cherry picked this originally didn't resolve
the ConnectivityService.java merge properly and left
out the ConnectivityService.java changes.

--- original commit by @Whitehawkx ---
Add an option to change the device hostname (1/2).

This adds an option to modify the device hostname used
in ip resolution. This is useful when connecting to the
android device in a dynamic dhcp environment.

Change-Id: Ibbac92e48363fde1e625111f76144a0233a3db80