[COMMON] Add missing labels for etcd, mongo, postgres

Add labels for DB deployments to be compliant with Istio
and kiali requirements

Issue-ID: OOM-3230

Change-Id: I937d9f326dae8e2c2496eace2e919aa0b8eb0171
Signed-off-by: Andreas Geissler <andreas-geissler@telekom.de>
diff --git a/kubernetes/common/etcd/templates/statefulset.yaml b/kubernetes/common/etcd/templates/statefulset.yaml
index e228e6d..829e17b 100644
--- a/kubernetes/common/etcd/templates/statefulset.yaml
+++ b/kubernetes/common/etcd/templates/statefulset.yaml
@@ -15,26 +15,13 @@
 */}}
 apiVersion: apps/v1
 kind: StatefulSet
-metadata:
-  name: {{ include "common.fullname" .  }}
-  labels:
-    heritage: "{{ .Release.Service }}"
-    release: "{{ include "common.release" . }}"
-    chart: "{{ .Chart.Name }}-{{ .Chart.Version }}"
-    app: {{ include "common.name" . }}
+metadata: {{- include "common.resourceMetadata" . | nindent 2 }}
 spec:
-  serviceName: {{ include "common.servicename" .}}
+  selector: {{- include "common.selectors" . | nindent 4 }}
+  serviceName: {{ include "common.servicename" . }}
   replicas: {{ .Values.replicaCount }}
-  selector:
-    matchLabels:
-      app: {{ include "common.name" .  }}
   template:
-    metadata:
-      labels:
-        heritage: "{{ .Release.Service }}"
-        release: "{{ include "common.release" . }}"
-        chart: "{{ .Chart.Name }}-{{ .Chart.Version }}"
-        app: {{ include "common.name" . }}
+    metadata: {{- include "common.templateMetadata" . | nindent 6 }}
     spec:
 {{- if .Values.affinity }}
       affinity: