Make /dev/kvm permissions handling more robust

This makes use of udev rules to make it smarter and override
host-level packages settings.
Additionally, this masks Ubuntu-only service that is another
pain point in terms of /dev/kvm permissions.
Fingers crossed for no further surprises.

Change-Id: I61235b51e2e1325b8a9b4f85bf634f663c7ec3cc
Closes-bug: #1681461