External Redis Configuration

allows for overidding of the default argocd redis full name

example yaml:

addons:
  argocd:
    enabled: true
    values:
      redis:
        host: "external-redis-url.amazonaws.com"
        port: 6379

relates to platform-one/big-bang/bigbang#1083

chart/templates/argocd-application-controller/deployment.yaml

@@ -66,6 +66,10 @@ spec:
         - --redis
         - {{ template "argo-cd.redis.fullname" . }}:{{ .Values.redis.servicePort }}
         {{- end }}
+        {{- if .Values.redis.externalEndpoint }}
+        - --redis
+        - {{ .Values.redis.externalEndpoint }}
+        {{- end }}
         {{- with .Values.controller.extraArgs }}
         {{- . | toYaml | nindent 8 }}
         {{- end }}