Automatic merge from submit-queue (batch tested with PRs 51416, 53535). 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>.
PodSecurityPolicy: teach fuzzer about fsGroup/supplementalGroups strategies
**What this PR does / why we need it**:
At present, fuzzer for PSP doesn't take into account `fsGroup`/`supplementalGroups` strategies. This PR teach fuzzer about these strategies in order to have ability to catch more possible errors.
**Special notes for your reviewer**:
Let me know if you think that we need to cover more (all?) fields in the PSP.
**Release note**:
```release-note
NONE
```
PTAL @pweil- @sttts
CC @simo5
7acb055aa2