Make cluster domain configurable for OMEC charts

Also, added chart icon.

Change-Id: I34d806b72fdbad058cab02732b5678900e5f5290
diff --git a/omec/omec-control-plane/templates/_helpers.tpl b/omec/omec-control-plane/templates/_helpers.tpl
index 223a933..53bd471 100644
--- a/omec/omec-control-plane/templates/_helpers.tpl
+++ b/omec/omec-control-plane/templates/_helpers.tpl
@@ -44,9 +44,9 @@
 {{- $type := index . 1 -}}
 {{- $context := index . 2 -}}
 {{- if eq $type "identity" -}}
-{{- printf "%s-s6a.%s.svc.%s" $service $context.Release.Namespace "cluster.local" -}}
+{{- printf "%s-s6a.%s.svc.%s" $service $context.Release.Namespace $context.Values.config.clusterDomain -}}
 {{- else if eq $type "realm" -}}
-{{- printf "%s.svc.%s" $context.Release.Namespace "cluster.local" -}}
+{{- printf "%s.svc.%s" $context.Release.Namespace $context.Values.config.clusterDomain -}}
 {{- else if eq $type "host" -}}
 {{- printf "%s-s6a" $service -}}
 {{- end -}}