Add k8s metallb switch parameter in k8s models

Use part of private adresses pool for metallb addresses.
By default metallb is disabled.

Change-Id: I60f62abbbf5681a91304c88560912f43802a89f2
Related-PROD: PROD-21474
diff --git a/classes/cluster/k8s-ha-calico-flannel-virtlet/kubernetes/init.yml b/classes/cluster/k8s-ha-calico-flannel-virtlet/kubernetes/init.yml
index eaf709b..02e61af 100644
--- a/classes/cluster/k8s-ha-calico-flannel-virtlet/kubernetes/init.yml
+++ b/classes/cluster/k8s-ha-calico-flannel-virtlet/kubernetes/init.yml
@@ -87,9 +87,12 @@
     kubernetes_externaldns_image: mirantis/external-dns:latest
     kubernetes_externaldns_provider: coredns
 
+    kubernetes_metallb_addresses_pool: 172.16.10.60-172.16.10.80
+
     # switches of addons
     kubernetes_coredns_enabled: false
     kubernetes_externaldns_enabled: false
+    kubernetes_metallb_enabled: false
 
   linux:
     network: