Automatic merge from submit-queue (batch tested with PRs 44191, 44117, 44072)
Fix pv upgrade test failure
**What this PR does / why we need it**:
2 changes were made that broke the pv upgrade test:
1. MakePod() was changed so that the volume mount point is at /mnt/volume<n> instead of /mnt. This change updates the path that the pod writes to.
2. The MakePod() call was changed to CreatePod(), which creates the pod and expects a long running pod. But the upgrade test uses a short running pod, and the call to TestContainerOutput() will also create the pod. This changes it back to MakePod()
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes#44168
**Special notes for your reviewer**:
**Release note**:
NONE