Add redis metadata for ceilometer

Add coordination_backend:redis metadata structure

Add the following softparams and set their defaults:
  ceilometer_redis_db
  ceilometer_redis_sentinel_mastername

Related-Prod: PROD-29126

Change-Id: I4ed496bae6e93db025980ee88a253a6e06ffa35d
diff --git a/defaults/openstack/init.yml b/defaults/openstack/init.yml
index 29d4aa2..290a511 100644
--- a/defaults/openstack/init.yml
+++ b/defaults/openstack/init.yml
@@ -79,6 +79,8 @@
     ceilometer_version: ${_param:openstack_version}
     ceilometer_upgrade_enabled: ${_param:openstack_upgrade_enabled}
     ceilometer_gnocchi_archive_policy: default
+    ceilometer_redis_db: ${_param:openstack_telemetry_redis_db}
+    ceilometer_redis_sentinel_mastername: ${_param:openstack_telemetry_redis_sentinel_mastername}
     # Gnocchi
     gnocchi_memcache_security_enabled: ${_param:openstack_memcache_security_enabled}
     gnocchi_memcache_secret_key: ''