Daishi Nakajima authored Aug 30, 2020 and Marge Bot committed Sep 08, 2020

this was suggested in #18417.

Change the print format of the values.
* Shorten commit hash
* Reduce precision of the "Value" field
* Shorten metrics name
  * e.g. runtime/bytes allocated -> run/alloc
* Shorten "MetricsChange"
  * e.g. unchanged -> unch, increased -> incr

And, print the baseline environment if there are baselines that were
measured in a different environment than the current environment.

If all "Baseline commit" are the same, print it once.