don't pass xos_repo_url and xos_repo_branch unless set by caller
remove playbook defaults that are already set as role defaults

Change-Id: I5929ace60b7941cde9100a440a9331c12fd629b1
diff --git a/vars/cord_single_defaults.yml b/vars/cord_single_defaults.yml
index e5890d4..56399a2 100644
--- a/vars/cord_single_defaults.yml
+++ b/vars/cord_single_defaults.yml
@@ -13,9 +13,7 @@
 
 service_profile_repo_dest: "~/service-profile"
 
-xos_configuration: cord-pod
-
-xos_repo_branch: "master"
+xos_configuration: cord-pod-ansible
 
 xos_container_rebuild: True