Avoid empty pod UID in test.
Avoid empty pod UID in test.

keegancsmith/prometheus,keegancsmith/prometheus,alileza/prometheus,GoogleCloudPlatform/prometheus,AlekSi/prometheus,amorken/prometheus,keegancsmith/prometheus,amorken/prometheus,brancz/prometheus,kangwoo/prometheus,amorken/prometheus,alileza/prometheus,brancz/prometheus,Stackdriver/stackdriver-prometheus,Conorbro/prometheus,keegancsmith/prometheus,GoogleCloudPlatform/prometheus,GoogleCloudPlatform/prometheus,Conorbro/prometheus,prometheus/prometheus,alileza/prometheus,keegancsmith/prometheus,amorken/prometheus,prometheus/prometheus,brancz/prometheus,Stackdriver/stackdriver-prometheus,Stackdriver/stackdriver-prometheus,brancz/prometheus,Gouthamve/prometheus,alileza/prometheus,AlekSi/prometheus,GoogleCloudPlatform/prometheus,prometheus/prometheus,AlekSi/prometheus,Conorbro/prometheus,prometheus/prometheus,Gouthamve/prometheus,Conorbro/prometheus,kangwoo/prometheus,kangwoo/prometheus,AlekSi/prometheus,Stackdriver/stackdriver-prometheus,alileza/prometheus,Gouthamve/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,Gouthamve/prometheus,kangwoo/prometheus