[CORD-3026] Unify the usage of imagePullPolicy in helm-charts

Change-Id: I6135a81060eeb7f2831ce9c7207339f92017c10e
diff --git a/onos/values.yaml b/onos/values.yaml
index 601e46d..795176a 100644
--- a/onos/values.yaml
+++ b/onos/values.yaml
@@ -20,10 +20,8 @@
 
 replicaCount: 1
 
-image:
-  repository: onosproject/onos
-  tag: 1.13.1
-  pullPolicy: IfNotPresent
+imagePullPolicy: IfNotPresent
+onosImage: 'onosproject/onos:1.13.1'
 
 nameOverride: ""
 fullnameOverride: ""