[infra] Print correct configuration groups in failures link
[infra] Print correct configuration groups in failures link

We were printing groups of builder names, not configurations

Change-Id: Ia9a6791fbd25939f71a1aa227bc288197c838bd6
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/133991
Reviewed-by: Martin Kustermann <a35dd5b79fac84b2bb3b026a16b8becc55af5961@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk