Add NeutronDhcpAgentDnsmasqEnableAddr6List param

Add boolean parameter ``NeutronDhcpAgentDnsmasqEnableAddr6List``
to support the ``dnsmasq_enable_addr6_list`` option in dhcp
agent settings.

Related-Bug: #1861032
Depends-On: https://review.opendev.org/704436
Depends-On: https://review.opendev.org/710335
Depends-On: https://review.opendev.org/725636
Change-Id: I69651b7e3390b5239097a9638ac1dc83a12fe96f
(cherry picked from commit 4ebcdc4443)

deployment/neutron/neutron-dhcp-container-puppet.yaml

@@ -141,6 +141,12 @@ parameters:
                  no AZs will be configured for Neutron network services.
     default: ''
     type: string
+  NeutronDhcpAgentDnsmasqEnableAddr6List:
+    default: true
+    description: |
+      Enable dhcp-host entry with list of addresses when port has multiple
+      IPv6 addresses in the same subnet.
+    type: boolean
 
 conditions:
 
@@ -204,6 +210,7 @@ outputs:
             neutron::agents::dhcp::dnsmasq_dns_servers: {get_param: NeutronDhcpAgentDnsmasqDnsServers}
             neutron::agents::dhcp::interface_driver: {get_param: NeutronInterfaceDriver}
             neutron::agents::dhcp::dhcp_broadcast_reply: {get_param: NeutronDhcpServerBroadcastReply}
+            neutron::agents::dhcp::dnsmasq_enable_addr6_list: {get_param: NeutronDhcpAgentDnsmasqEnableAddr6List}
             neutron::agents::dhcp::debug:
               if:
               - service_debug_unset

releasenotes/notes/neutron-add-dnsmasq_enable_addr6_list-ead32a7739431607.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    Add boolean parameter ``NeutronDhcpAgentDnsmasqEnableAddr6List`` to support
+    the ``dnsmasq_enable_addr6_list`` option in dhcp agent settings.
+    (See bug: `#1861032 <https://bugs.launchpad.net/neutron/+bug/1861032>`_)