Automatic merge from submit-queue (batch tested with PRs 48365, 49902, 49808, 48722, 47045)
Add admission controller API to runtime config and externalize ADMISSION_CONTROL
**What this PR does / why we need it**:
Enable the dynamic admission controller registration API by
adding "admissionregistration.k8s.io/v1alpha1" to --runtime-config
to fix problems when starting up local-up-cluster. Also make sure
ADMISSION_CONTROL can be specified externally.
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #
Fixes#47385
**Special notes for your reviewer**:
**Release note**:
```release-note
NONE
```
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