VOL-2110 - update how default image tags are managed

- Sneak in a work around for helm 2.15

Change-Id: Iabe4fa98b5b4a574061f1fac7a876b3f1f05c398
diff --git a/voltha-adapter-simulated/values.yaml b/voltha-adapter-simulated/values.yaml
index 6098a7d..62d524b 100644
--- a/voltha-adapter-simulated/values.yaml
+++ b/voltha-adapter-simulated/values.yaml
@@ -46,11 +46,11 @@
   adapter_simulated_olt:
     registry: '{{ .Values.defaults.image_registry }}'
     repository: '{{ .Values.defaults.image_org }}voltha-adapter-simulated-olt'
-    tag: '{{ if hasKey .Values.defaults "image_tag" }}{{ .Values.defaults.image_tag }}{{ else }}2.2.0{{ end }}'
+    tag: '{{- if hasKey .Values.defaults "image_tag" }}{{- if .Values.defaults.image_tag }}{{ .Values.defaults.image_tag }}{{- else }}2.2.0{{- end }}{{- else }}2.2.0{{- end }}'
     pullPolicy: '{{ .Values.defaults.image_pullPolicy }}'
 
   adapter_simulated_onu:
     registry: '{{ .Values.defaults.image_registry }}'
     repository: '{{ .Values.defaults.image_org }}voltha-adapter-simulated-onu'
-    tag: '{{ if hasKey .Values.defaults "image_tag" }}{{ .Values.defaults.image_tag }}{{ else }}2.2.0{{ end }}'
+    tag: '{{- if hasKey .Values.defaults "image_tag" }}{{- if .Values.defaults.image_tag }}{{ .Values.defaults.image_tag }}{{- else }}2.2.0{{- end }}{{- else }}2.2.0{{- end }}'
     pullPolicy: '{{ .Values.defaults.image_pullPolicy }}'