hmsclient doesn't set ugi on connection open with hms

[agnes-xinyi-lu]

Our hms users through hmsclient couldn't pass their user names to the server, which makes it difficult to debug when hms server side has some perf issue due to user queries.
We want to expose user and group parameters from hmsclient so there is a way from the client side to pass in the user info without having to add a wrapper on top of hmsclient.