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>.

Let webhook controller uses a local scheme that understand admissionReview

An alternative to #60965.
Fix #60963.
Fix kubernetes/sample-apiserver#21.

Created a scheme that only understands admission/v1beta1 and use it to
encode/decode admissionReviews.

cc @sttts