Merge branch '765-istio-ingressgateway-extraLabels' into 'master'

Resolve "Istio ingressgateway extraLabels value being stripped out"

Closes #765

See merge request platform-one/big-bang/bigbang!900

chart/templates/istio/controlplane/values.yaml

@@ -34,6 +34,9 @@ ingressGateways:
 {{- range $name, $values := .Values.istio.ingressGateways }}
   {{ $name | nindent 2 }}:
     {{- toYaml (merge (dict "k8s" $values.kubernetesResourceSpec) (fromYaml (include "istio.ingressgateway.k8s" $values))) | nindent 4 }}
+    {{- if $values.extraLabels }} 
+    {{- toYaml (dict "extraLabels" $values.extraLabels) | nindent 4 }}
+    {{- end}}
 {{- end }}
 
 {{- if .Values.istio.gateways }}