Also shortens ECH variable names in runner.go.
Bug: 275
Change-Id: Iaef520ae09eb94f714fbdaa4383d1456add6f113
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/47744
Commit-Queue: Dan McArdle <dmcardle@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>