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

Change-Id: I7f3457882830de050d1357254fc5483faf91d03f
diff --git a/xos-db/templates/db-deployment.yaml b/xos-db/templates/db-deployment.yaml
index a3d3e91..d467b05 100644
--- a/xos-db/templates/db-deployment.yaml
+++ b/xos-db/templates/db-deployment.yaml
@@ -28,8 +28,8 @@
     spec:
       containers:
         - name: xos-db
-          image: {{ .Values.postgresImage | quote }}
-          imagePullPolicy: {{ .Values.imagePullPolicy }}
+          image:  {{ .Values.global.registry }}{{ .Values.image.repository }}:{{ tpl .Values.image.tag . }}
+          imagePullPolicy: {{ .Values.image.pullPolicy }}
           ports:
             - containerPort: 5432
               protocol: TCP