Test: Check status sent by readClient

[yunhanw-google]

I wonder whether we can assert something about the message the other side got (i.e. the exact status the ReadClient sent). If not, please file a followup issue about making it possible. I have some thoughts on what we can do here if htere is not already an easy way.

Originally posted by @bzbarsky-apple in #21368 (comment)

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.