network, bridge binding: Enable container interface

In a scenario where a VM with a bridge binding interface set with MAC address
(e.g.: by human or KubeMacPool) on a cluster with IPv6 enabled (dual stack
or IPv6 single stack) is migrated, we observe packet drops at the inbound traffic
to the VM immediately after the migration target pod starts.
These packets are getting routed to the destination node before the migration completes.

When the migration target pod is created an IPv6 NS(Neighbor Solicitation) and NA
(Neighbor Advertisement) are sent automatically by the kernel.
The switches at the endpoints (e.g.: migration destination node) tables
get updated and the traffic is routed to the migration destination before
the migration is completed [1].

Following the bridge CNI RFE to disable the container interface to prevent the
container interface from sending IPv6 NS/NA [2], set bridge binding
interfaces' container interface state to up.

Fixes: https://issues.redhat.com/browse/CNV-28040

[1] https://bugzilla.redhat.com/show_bug.cgi?id=2186372#c6
[2] containernetworking/plugins#951

Signed-off-by: Or Mergi <ormergi@redhat.com>

pkg/network/setup/netpod/netpod.go

@@ -330,6 +330,7 @@ func (n NetPod) bridgeBindingSpec(podIfaceName string, vmiIfaceIndex int, ifaceS
 	podIface := nmstate.Interface{
 		Index:       podStatusIface.Index,
 		Name:        podIfaceAlternativeName,
+		State:       nmstate.IfaceStateUp,
 		CopyMacFrom: bridgeIface.Name,
 		Controller:  bridgeIface.Name,
 		IPv4:        nmstate.IP{Enabled: pointer.P(false)},