Metallb --lb-class cmd arg to support multiple LoadBalancer implementations (#10550)

* metallb --lb-class cmd arg to support multiple load balancer implementations

* removed loadbalancer_class from metallb_config; metallb_loadbalancer_class in role defaults

roles/kubernetes-apps/metallb/defaults/main.yml

@@ -13,3 +13,4 @@ metallb_speaker_tolerations:
     key: node-role.kubernetes.io/control-plane
     operator: Exists
 metallb_controller_tolerations: []
+metallb_loadbalancer_class: ""

roles/kubernetes-apps/metallb/templates/metallb.yaml.j2

@@ -1724,6 +1724,9 @@ spec:
       - args:
         - --port={{ metallb_port }}
         - --log-level={{ metallb_log_level }}
+{% if metallb_loadbalancer_class != "" %}
+        - --lb-class={{ metallb_loadbalancer_class }}
+{% endif %}
         env:
         - name: METALLB_ML_SECRET_NAME
           value: memberlist
@@ -1814,6 +1817,9 @@ spec:
       - args:
         - --port={{ metallb_port }}
         - --log-level={{ metallb_log_level }}
+{% if metallb_loadbalancer_class != "" %}
+        - --lb-class={{ metallb_loadbalancer_class }}
+{% endif %}
         env:
         - name: METALLB_NODE_NAME
           valueFrom: