[2/2] Settings: Add an option to change the device hostname

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.

PS4
move to end of first section

Change-Id: Ib04d551b7eb31110962709e0d956db4da380175a
Merge branch 'android-4.4' of https://github.com/omnirom/android_packages_apps_Settings into android-4.4