Automatic merge from submit-queue

Specific error message on failed rolling update issued by older kubectl against 1.4 master

Fix #32706

`kubernetes-e2e-gke-1.4-1.3-kubectl-skew` (1.3 kubectl and 1.4 master) test suite failed with:
```
k8s.io] Kubectl client [k8s.io] Kubectl rolling-update should support rolling-update to same image [Conformance]
...
Error from server: object is being deleted: replicationcontrollers "e2e-test-nginx-rc" already exists error: exit status 1 not to have occurred
```

It's because the old RC had an orphanFinalizer, so it is not deleted from the key-value store immediately. In turn, the creation of the new RC of the same name failed. 

In this failure, the RC and pods are updated, it's just that the RC is of different name, i.e., original name + a hash generated based on podTemplate. The error is confusing to user, but not that bad. So this PR just prints a warning message to instruct users how to work around.

1.4 kubectl rolling-update uses different logic so it's working.

@lavalamp @gmarek @janetkuo @pwittrock 

cc @liggitt for the ctx changes.