Automatic merge from submit-queue (batch tested with PRs 41931, 39821, 41841, 42197, 42195)

Admission Controller: Add Pod Preset

Based off the proposal in https://github.com/kubernetes/community/pull/254

cc @pmorie @pwittrock 

TODO:
- [ ] tests



**What this PR does / why we need it**: Implements the Pod Injection Policy admission controller

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

**Special notes for your reviewer**:

**Release note**:

```release-note
Added new Api `PodPreset` to enable defining cross-cutting injection of Volumes and Environment into Pods.
```