Automatic merge from submit-queue (batch tested with PRs 41667, 41820, 40910, 41645, 41361)

Allow multiple mounts in StatefulSet volume zone placement

We have some heuristics that ensure that volumes (and hence stateful set
pods) are spread out across zones.  Sadly they forgot to account for
multiple mounts.  This PR updates the heuristic to ignore the mount name
when we see something that looks like a statefulset volume, thus
ensuring that multiple mounts end up in the same AZ.

Fix #35695

```release-note
Fix zone placement heuristics so that multiple mounts in a StatefulSet pod are created in the same zone
```