Add log on connection close done by Citadel Agent (#15539)
Add log on connection close done by Citadel Agent (#15539)

* add log on connection close

* update

smawson/istio,smawson/istio,istio/istio,geeknoid/istio,geeknoid/istio,istio/istio,smawson/istio,istio/istio,geeknoid/istio,istio/istio,istio/istio,smawson/istio,smawson/istio,geeknoid/istio,geeknoid/istio,smawson/istio,geeknoid/istio