For non-XOS charts, use a global registry var, split docker image name/tag/pullPolicy

Change-Id: Icffc569e2c152e0b413f4c7b7d9a546bd9a3ef58
diff --git a/abstract-olt/values.yaml b/abstract-olt/values.yaml
index 1ef023c..ce34037 100644
--- a/abstract-olt/values.yaml
+++ b/abstract-olt/values.yaml
@@ -23,6 +23,9 @@
   tag: '{{ .Chart.AppVersion }}'
   pullPolicy: Always
 
+global:
+  registry: ''
+
 service:
   type: NodePort
   grpcPort: 31777
@@ -36,4 +39,4 @@
 
 affinity: {}
 
-annotations: {}
\ No newline at end of file
+annotations: {}