[udev] initrd xenial doesn't include biosdevname

[JulienPrigent]

The former version of ubuntu-installer (14.04) included an initrd.gz with the biosdevname binary and 71-biosdevname.rules for udev.

Since 16.04, there is no more biosdevname traces in the ubuntu-installer.
That induces a different name for network card (e.g eno1 instead of em1) during installing phase.

It's a backward compatibility issue for preseed and post-installation scripts as they become deprecated (even with the same hardware).

Futhermore, if you install biosdevname on the fresh install, your network card will fall back to the old 14.04 (em1) scheme... That's really disruptive when one wants to automatize and deploy at scale.