Merge branch 'master' into restrict-service-monitor

hack/example-service-monitoring/deploy

hack/example-service-monitoring/teardown

hack/scripts/generate-rules-configmap.sh

manifests/examples/example-app/example-app.yaml

...metheus-frontend-alertmanager-discovery-role-binding.yaml

...-app/prometheus-frontend-alertmanager-discovery-role.yaml

...ples/example-app/prometheus-frontend-service-account.yaml

manifests/examples/example-app/prometheus-frontend-svc.yaml

manifests/examples/example-app/servicemonitor-frontend.yaml

manifests/prometheus/prometheus-k8s-rules.yaml

manifests/prometheus/prometheus-k8s.yaml