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

Change-Id: I7f3457882830de050d1357254fc5483faf91d03f
diff --git a/xos-services/vtn-service/values.yaml b/xos-services/vtn-service/values.yaml
index 6c25d21..f15fd29 100644
--- a/xos-services/vtn-service/values.yaml
+++ b/xos-services/vtn-service/values.yaml
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Default values for TTN
+# Default values for VTN
 # This is a YAML-formatted file.
 # Declare variables to be passed into your templates.
 
@@ -22,9 +22,13 @@
 nameOverride: ""
 fullnameOverride: ""
 
-imagePullPolicy: 'Always'
+image:
+  repository: 'xosproject/vtn-synchronizer'
+  tag: '{{ .Chart.AppVersion }}'
+  pullPolicy: 'Always'
 
-vtn_synchronizerImage: "xosproject/vtn-synchronizer:{{ .Chart.Version }}"
+global:
+  registry: ''
 
 xosAdminUser: "admin@opencord.org"
 xosAdminPassword: "letmein"