Add redis metadata for aodh

Add coordination_backend:redis metadata structure

Add the following softparams and set their defaults:
    aodh_redis_db
    aodh_redis_sentinel_mastername

Related-Prod: PROD-29126

Change-Id: I92d31cc5ca54eb1a907895e0a32d9a99b5b0921e
diff --git a/defaults/openstack/init.yml b/defaults/openstack/init.yml
index 97382de..29d4aa2 100644
--- a/defaults/openstack/init.yml
+++ b/defaults/openstack/init.yml
@@ -72,6 +72,8 @@
     aodh_old_version: ${_param:openstack_old_version}
     aodh_version: ${_param:openstack_version}
     aodh_upgrade_enabled: ${_param:openstack_upgrade_enabled}
+    aodh_redis_db: ${_param:openstack_telemetry_redis_db}
+    aodh_redis_sentinel_mastername: ${_param:openstack_telemetry_redis_sentinel_mastername}
     # Ceilometer
     ceilometer_old_version: ${_param:openstack_old_version}
     ceilometer_version: ${_param:openstack_version}