Add proxy healthz result to ETP=local health check

Today, the health check response to the load balancers asking Kube-proxy for
the status of ETP:Local services does not include the healthz state of Kube-
proxy. This means that Kube-proxy might indicate to load balancers that they
should forward traffic to the node in question, simply because the endpoint
is running on the node - this overlooks the fact that Kube-proxy might be
not-healthy and hasn't successfully written the rules enabling traffic to
reach the endpoint.

pkg/proxy/iptables/proxier.go

@@ -268,7 +268,7 @@ func NewProxier(ipFamily v1.IPFamily,
 	masqueradeMark := fmt.Sprintf("%#08x", masqueradeValue)
 	klog.V(2).InfoS("Using iptables mark for masquerade", "ipFamily", ipt.Protocol(), "mark", masqueradeMark)
 
-	serviceHealthServer := healthcheck.NewServiceHealthServer(hostname, recorder, nodePortAddresses)
+	serviceHealthServer := healthcheck.NewServiceHealthServer(hostname, recorder, nodePortAddresses, healthzServer)
 
 	proxier := &Proxier{
 		svcPortMap:               make(proxy.ServicePortMap),