Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Switch kubectl convert back to use legacyscheme and add tests
Revert the change of `convert.go` in #54533.
Add tests for kubectl convert.
Fixes#54873
```release-note
NONE
```
cc: @smarterclayton
fcf9b1f7e5