Add galera system level upgrade metadata

Change-Id: I610e290986189704da54a8386d62b4c3b27c8d52
Related-prod: PROD-29630
(cherry picked from commit b8fb87471b1a8e295048ad2036409f1a457d1100)
diff --git a/defaults/openstack/init.yml b/defaults/openstack/init.yml
index 61af318..19b3fe8 100644
--- a/defaults/openstack/init.yml
+++ b/defaults/openstack/init.yml
@@ -26,6 +26,8 @@
     openstack_rabbitmq_x509_enabled: False
     # RabbitMQ
     rabbitmq_upgrade_enabled: ${_param:openstack_upgrade_enabled}
+    # Galera
+    galera_upgrade_enabled: ${_param:openstack_upgrade_enabled}
     # Openstack memcache
     openstack_memcached_server_bind_address: 0.0.0.0
     openstack_memcache_security_enabled: False