By default libvirt does not allow traffic destined for other MAC
addresses to reach VMs when using a macvtap interface. This prevents
multicast from working.
This change fixes the issue by setting libvirt_vm_trust_guest_rx_filters
to true.
Depends-On: https://review.opendev.org/736249
Change-Id: I71a2051d8acd63379bd70bc1287a059d4a7f6387