Encountered following failure in 4.5 CI:
https://prow.svc.ci.openshift.org/view/gcs/origin-ci-test/logs/release-openshift-origin-installer-e2e-gcp-4.5/1627

[sig-instrumentation] Prometheus when installed on the cluster should have a AlertmanagerReceiversNotConfigured alert in firing state [Suite:openshift/conformance/parallel] expand_less 	1m38s
fail [github.com/openshift/origin/test/extended/prometheus/prometheus_builds.go:167]: Expected
    <map[string]error | len:1>: {
        "ALERTS{alertstate=\"firing\",alertname=\"AlertmanagerReceiversNotConfigured\"} == 1": {
            s: "promQL query: ALERTS{alertstate=\"firing\",alertname=\"AlertmanagerReceiversNotConfigured\"} == 1 had reported incorrect results:\n[]",
        },
    }
to be empty