Automatic merge from submit-queue (batch tested with PRs 52843, 52710, 52821, 52844). 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>..

update-staging-godeps: only mangle staging repos in staging Godeps.json

- this re-adds non-staging k8s.io/* repos to the staging Godeps.jsons
- x-outs instead of removing of staging dependencies in order to get a
  precise trigger for a complete godep restore+save run in the publisher
  bot.

The first breaks k8s.io/kube-aggregator's staging export.

The second potentially leads to inconsistent godeps in our exported staging repos.