[infra] Improve output messages of get_builder_status.dart
[infra] Improve output messages of get_builder_status.dart

Change-Id: Icb16e9408a5f15e774d5c2adafc0eaf507c2ce7f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/130367
Reviewed-by: Karl Klose <49bc0b76cffb0b10cd8c84f9cabc97a31ffe6343@google.com>
Commit-Queue: William Hesse <a821cddceae7dc400f272e3cb1a72f400f9fed6d@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