add segmentation id option to octavia mgmt network creation task

Change-Id: I2c7868a6e71222ecd7b7a3315574d6112b65312d

defaults/main.yml

@@ -308,6 +308,8 @@ octavia_neutron_management_network_name: lbaas-mgmt
 octavia_provider_network_name: lbaas
 # Network type
 octavia_provider_network_type: flat
+# Network segmentation ID if vlan, gre...
+#octavia_provider_segmentation_id:
 # Network CIDR
 octavia_management_net_subnet_cidr: 172.29.232.0/22
 # Do we require the Neutron DHCP server

tasks/octavia_mgmt_network.yml

@@ -30,6 +30,7 @@
     name: "{{ octavia_neutron_management_network_name }}"
     provider_network_type: "{{ octavia_provider_network_type }}"
     provider_physical_network: "{{ octavia_provider_network_name }}"
+    provider_segmentation_id: "{{ octavia_provider_segmentation_id | default(omit) }}"
   when: octavia_service_net_setup
 
 - name: Ensure mgmt subnet exists