Non-federated zone CP doesn't add kuma.io/zone label on policies

[lobkovilya]

What happened?

Policy without kuma.io/zone label can't reference MeshService with kuma.io/zone label.

1. Start zone CP
2. Create MeshService backend
3. Apply MeshHTTPRoute

   type: MeshHTTPRoute
   name: mesh-service-route-1
   mesh: mesh-service
   labels:
     kuma.io/origin: zone # when this is missing we don't have kuma.io/zone
   spec:
     targetRef:
       kind: MeshSubset
       tags:
         kuma.io/service: demo-client
     to:
       - targetRef:
           kind: MeshService
           name: backend
           sectionName: "80" 
         rules:
           - matches:
             - path:
                 value: /instance1
                 type: PathPrefix
             default:
               backendRefs:
                 - kind: MeshService
                   name: backend
                   port: 80
           - matches:
             - path:
                 value: /instance2
                 type: PathPrefix
             default:
               backendRefs:
                 - kind: MeshService
                   name: backendsecond
                   port: 80

[lahabana]

@lobkovilya to check if this is still the case or not

[lahabana]

If this is still the case and it's not a problem for migrating to federated then just punt this to 2.10.x

[lobkovilya]

Tested both k8s and uni non-federated zones and it works as expected.