improve grouping label match logic
improve grouping label match logic

Signed-off-by: yeya24 <730e4ef81dca03ba0c5a00c612d6b33341278a96@gmail.com>

keegancsmith/prometheus,keegancsmith/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,prometheus/prometheus,prometheus/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,alileza/prometheus,keegancsmith/prometheus,alileza/prometheus,GoogleCloudPlatform/prometheus,keegancsmith/prometheus,keegancsmith/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,alileza/prometheus,alileza/prometheus,GoogleCloudPlatform/prometheus,alileza/prometheus