Automatic merge from submit-queue (batch tested with PRs 59310, 60424, 60308, 60436, 60020). 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 number of pods created for local PV stress test

**What this PR does / why we need it**:
Local PV stress test is flaking.  Failed runs show that test is timing out at 47/50 pods.  Reduce the number of pods created by the test so that it's not so close to the max timeout.

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

**Special notes for your reviewer**:
I'll need to investigate further to see why processing the pods is so slow and ways to speed it up.  But for now, try to reduce flaking.

**Release note**:

```release-note
NONE
```