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>.
Bury KubeletConfiguration.ConfigTrialDuration for now
Based on discussion in https://github.com/kubernetes/kubernetes/pull/53833/files#r166669046, this PR chooses not to expose a knob for the trial duration yet. It is unclear exactly which shape this functionality should take in the API.
```release-note
The alpha KubeletConfiguration.ConfigTrialDuration field is no longer available.
```