set vault agent uid/gid to prometheus uid/gid to allow token access

chart/templates/monitoring/values.yaml

@@ -247,6 +247,8 @@ prometheus:
         vault.hashicorp.com/agent-init-first: "true"
         vault.hashicorp.com/agent-inject-token: "true"
         vault.hashicorp.com/role: "prometheus"
+        vault.hashicorp.com/agent-run-as-user : "1000"
+        vault.hashicorp.com/agent-run-as-group : "2000"
         {{- end }}
       {{- end }}
     {{- if .Values.addons.vault.enabled }}