Add pull_docker_registry

Change-Id: Ic255aa0b800012c52c478dcd5228a598b4ff3b9b
diff --git a/roles/onos-fabric-install/defaults/main.yml b/roles/onos-fabric-install/defaults/main.yml
index 367727e..7576ddb 100644
--- a/roles/onos-fabric-install/defaults/main.yml
+++ b/roles/onos-fabric-install/defaults/main.yml
@@ -5,7 +5,7 @@
 head_onos_fabric_dir: "/opt/onos_fabric/"
 
 # ONOS docker image to use
-deploy_docker_registry: ""
-deploy_docker_tag: "candidate"
-onos_docker_image: "{{ deploy_docker_registry }}onosproject/onos:{{ deploy_docker_tag }}"
+pull_docker_registry: ""
+pull_docker_tag: "candidate"
+onos_docker_image: "{{ pull_docker_registry }}onosproject/onos:{{ pull_docker_tag }}"