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

Change-Id: I7f3457882830de050d1357254fc5483faf91d03f
diff --git a/xos-services/exampleservice/Chart.yaml b/xos-services/exampleservice/Chart.yaml
index cf29f5d..2583804 100644
--- a/xos-services/exampleservice/Chart.yaml
+++ b/xos-services/exampleservice/Chart.yaml
@@ -15,4 +15,8 @@
 
 name: exampleservice
 description: A Helm chart for XOS's "exampleservice" service
-version: 2.1.0
+icon: https://guide.opencord.org/logos/cord.svg
+
+version: 2.1.2
+appVersion: 2.1.2
+