Update OverloadStatistics to match prop 328

Closes: #40940 (closed).

Hrm, this is supposed to be against maint-0.4.8, so maybe I've targeted the wrong branch? Might still be fine...

requested review from @ahf

changed milestone to %Tor: 0.4.9.x-freeze

approved this merge request

@gk You want it in for 0.4.8? That is fine, I just need to manually merge it then (and change milestone here)

Yes, please.

I have cherry pick the commit into 048 and merge forward. Thanks!

closed