Add etcd single server installation

Change-Id: I13e47500f0ef0bc0fbb33e8fed56ba606e7f85c1
Related-prod: #PROD-28243 (PROD:28243)
diff --git a/defaults/init.yml b/defaults/init.yml
index db9fca9..b70367e 100644
--- a/defaults/init.yml
+++ b/defaults/init.yml
@@ -24,6 +24,8 @@
 - system.defaults.stacklight
 - system.defaults.xtrabackup
 - system.defaults.backup
+# k8s
+- system.defaults.etcd
 parameters:
   _param:
     mcp_version: stable