Make "kubecfg -s <port> run ..." select correctly

kubecfg run creates a replication controller which sets all pods with a
replicationController= label, but then sets up a service selecting on name=
instead.  This fixes that.  kubecfg -s <port> run ... can now actually work.
Note that if we change the labels used, the e2etest apparently needs to be updated here:
https://github.com/GoogleCloudPlatform/kubernetes/blob/master/hack/e2e-suite/update.sh#L33