XOS/NEM charts, use a global registry var, split docker image name/tag/pullPolicy

Change-Id: I7f3457882830de050d1357254fc5483faf91d03f
diff --git a/xos-services/onos-service/Chart.yaml b/xos-services/onos-service/Chart.yaml
index 248ffbf..8c92ab6 100644
--- a/xos-services/onos-service/Chart.yaml
+++ b/xos-services/onos-service/Chart.yaml
@@ -15,4 +15,5 @@
 
 description: A Helm chart for XOS's "onos-service" service, which configures ONOS
 name: onos-service
-version: 2.0.2-dev
+version: 2.0.5
+appVersion: 2.0.5