VOL-3657 support stack id in rpc events by passing stack id through helm chart

Change-Id: Id45c5984540265eb40df77de979f732080908656
diff --git a/voltha-stack/values.yaml b/voltha-stack/values.yaml
index dea3bad..74015e1 100644
--- a/voltha-stack/values.yaml
+++ b/voltha-stack/values.yaml
@@ -30,6 +30,7 @@
     enableVirtualHosts: false
   rw_core:
     kv_store_data_prefix: 'service/voltha/{{ .Release.Name }}_{{ .Values.global.stack_name }}'
+    stack_id: "{{ .Values.global.stack_name }}"
     topics:
       core_topic: "{{ .Release.Name }}_{{ .Values.global.stack_name }}_rwcore"
   services: