Comment 4 for bug 1999445

On Debian this libvirt and qemu users/groups setup changed a bit and seems to be easier to maintain.
Previously there was no mismatch between the container kvm GID and the host kvm GID because both had our qemu rpm installed and it was forcing the GID to 36 [1].

After a bit of digging around the history of debian/qemu I found the following timeline:

* The kvm group was firstly created by the qemu-system.postinst script [2]
* Then, it was moved to the qemu-system-common.postinst script [3]
* Finally, it was removed at all [4], relying now on the debian/systemd patch [5] that already creates the group and sets the device (/dev/kvm) permissions and ownership accordingly.

Since on Debian sytemd is already creating the kvm group and handling the /dev/kvm permission and ownership, we can remove this step from our libvirt container setup script (libvirt.sh [6]) and rely on Debian installation defaults. Will create an openstack-helm-infra patch for it.

[1] https://opendev.org/starlingx/integ/src/branch/master/virt/qemu/centos/qemu-kvm.spec#L722
[2] https://salsa.debian.org/qemu-team/qemu/-/commit/dbb34ed82d28a07afc24ecbf62ecdd0dfc34b741
[3] https://salsa.debian.org/qemu-team/qemu/-/blob/debian/qemu_2.1+dfsg-12+deb8u6/debian/qemu-system-common.postinst
[4] https://salsa.debian.org/qemu-team/qemu/-/commit/cb8737ef48a37eddf12ac199b46f9034273ba6d3
[5] https://salsa.debian.org/systemd-team/systemd/-/commit/4fc3fa53bfa6e16ceb6cd312f49003839b56144a
[6] https://github.com/openstack/openstack-helm-infra/blob/master/libvirt/templates/bin/_libvirt.sh.tpl#L36

The only thing that I still need to align is the container nova user/group addition to kvm group. I need to understand how it should align with users/groups on the host.