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>.

simplify kubectl testing factory

This simplifies and strips down the fake factory and collapses us down to a single fake!

@kubernetes/sig-cli-maintainers @juanvallejo 
/assign @pwittrock 
/assign @soltysh 

```release-note
NONE
```