Automatic merge from submit-queue
Let release_1_5 clientset include multiple versions of a group
Fix#35237
This PR make versioned clientset to include multiple versions of a group. Currently only `batch` has `v1` and `v2alpha1`. The clientset interface now looks like:
```go
BatchV2alpha1() v2alpha1batch.BatchV2alpha1Interface
BatchV1() v1batch.BatchV1Interface
// Deprecated: please explicitly pick a version if possible.
Batch() v1batch.BatchV1Interface
```
Commit "update client-gen to say internalversion rather than unversioned" fixes https://github.com/kubernetes/kubernetes/issues/24481.
cc @kubernetes/sig-api-machinery @soltysh @deads2k @nikhiljindal
```release-note
release_1_5 clientset supports multiple versions of a group.
```