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>.

Shutdown http handlers before shutting down audit backend

**What this PR does / why we need it**:
Currently, audit backend is shut down before http handlers stop processing requests, so some audit events can be dropped in case of batching webhook.

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #50781

**Special notes for your reviewer**:

**Release note**:

```release-note
Shutdown http handlers in kube-apiserver before shutting down audit backend.
```