Bug fix for virtctl expose Service creation

[Orel Misan]

Hello everyone,

I am writing to let you know of a bug we have in the `virtctl expose` command.

Almost four years ago, the `vm.kubevirt.io/name` label was introduced by [1] to be set on virt-launcher pods.
A year or so ago, the `virtctl expose` command was modified [2] to create the Service objects using the label above.

Unfortunately, the value of the label above can be surprising - as it could take the value of the VM's hostname field in case it exists.

I have proposed a backward-compatible fix in PR [3]. Your feedback would be greatly appreciated.

Best regards,

Orel

[1] https://github.com/kubevirt/kubevirt/pull/7102
[2] https://github.com/kubevirt/kubevirt/pull/13496
[3] https://github.com/kubevirt/kubevirt/pull/15783