tests: Activate VM interfaces and run dhcp server
tests: Activate VM interfaces and run dhcp server

Cirros has a very slow startup in case there is no dhcp server responding
to it. To allow using the same tests for dual stack and ipv6 only clusters,
tests using Cirros will now use Alpine.

Alpine VM starts with eth0 and lo interfaces down.
This commit is adding activation to those interfaces and running the dhcp
server.

Signed-off-by: Alona Kaplan <9ea2f88c7fe7e68aa51858b03e0d548211901b83@redhat.com>

kubevirt/kubevirt,kubevirt/kubevirt,kubevirt/kubevirt,kubevirt/kubevirt