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

Change-Id: I7f3457882830de050d1357254fc5483faf91d03f
diff --git a/xos-services/onos-service/values.yaml b/xos-services/onos-service/values.yaml
index ab52be0..21c4bbe 100644
--- a/xos-services/onos-service/values.yaml
+++ b/xos-services/onos-service/values.yaml
@@ -22,9 +22,13 @@
 nameOverride: ""
 fullnameOverride: ""
 
-imagePullPolicy: 'Always'
+image:
+  repository: 'xosproject/onos-synchronizer'
+  tag: '{{ .Chart.AppVersion }}'
+  pullPolicy: 'Always'
 
-onos_synchronizerImage: "xosproject/onos-synchronizer:master"
+global:
+  registry: ""
 
 xosAdminUser: "admin@opencord.org"
 xosAdminPassword: "letmein"