Describe the enhancement requested

https://lists.apache.org/thread/pc9fs0hf8t5ylj9os00r9vg8d2xv2npz

Add a way that services can explicitly indicate to clients that they may reuse the connection used to get FlightInfo to also fetch data, instead of requiring the service to somehow know or figure out its public address (which may be difficult when proxies, etc. are involved).

Component(s)

C++, FlightRPC, Go, Java