Make number of Octavia controller workers configurable

Also increase default number of workers to 2.

Change-Id: I6fbe6b62b2fa61aefd7014b5e50fba5670885fde
Related-PROD: PROD-34519
diff --git a/metadata/service/manager/cluster.yml b/metadata/service/manager/cluster.yml
index 4050391..058f6e4 100644
--- a/metadata/service/manager/cluster.yml
+++ b/metadata/service/manager/cluster.yml
@@ -6,6 +6,7 @@
   _param:
     keystone_octavia_endpoint_type: internal
     octavia_loadbalancer_topology: 'SINGLE'
+    octavia_controller_worker_number: 2
     octavia_hm_bind_port: 5555
     octavia_amphora_availability_zone: 'nova'
     octavia_worker_connection_max_retries: 500
@@ -41,6 +42,7 @@
         ca_private_key: '/etc/octavia/certs/ca.key'
         ca_certificate: '/etc/octavia/certs/ca_01.pem'
       controller_worker:
+        workers: ${_param:octavia_controller_worker_number}
         amp_flavor_id: ${_param:amp_flavor_id}
         amp_image_tag: amphora
         amp_ssh_key_name: octavia_ssh_key