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>.

Reduce memory footprint of admission metrics

Fix #56061

Remove `SummaryVec` from all but the top level metric and reduce buckets for the histogram from 7 to 5.

For a small test cluster, the `Individual Memory Usage: kube-system kube-apiserver-kubernetes-master` grafana metric suggests showed the memory footprint of apiserver at 655MB before this change and 415MB after, suggesting this accounts for the vast majority of the ~200MB of memory increase found in #56061.

```release-note
None
```