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>.

staging-repos: add note that these are to be imported as k8s/*

Fixes https://github.com/kubernetes/sample-controller/issues/17
Fixes https://github.com/kubernetes/sample-controller/issues/20