Show empty routes in pc routes (#28170)
Show empty routes in pc routes (#28170)

```
NOTE: This output only contains routes loaded via RDS.
NAME                                                                                                     DOMAINS                      MATCH                  VIRTUAL SERVICE
https.443.https-443-ingress-service1-default-0.service1-istio-autogenerated-k8s-ingress.istio-system     *                            /*                     404
https.443.https-443-ingress-service2-default-0.service2-istio-autogenerated-k8s-ingress.istio-system     *                            /*                     404
http.80                                                                                                  service1.demo.........io     /*                     service1-demo-......-io-service1-istio-autogenerated-k8s-ingress.default
http.80                                                                                                  service2.demo.........io     /*                     service2-demo-.....i-io-service2-istio-autogenerated-k8s-ingress.default
                                                                                                         *                            /stats/prometheus*
                                                                                                         *                            /healthz/ready*
```

The first 2 lines would not show up without this PR
istio/istio,istio/istio,istio/istio,istio/istio,istio/istio