Automatic merge from submit-queue (batch tested with PRs 49651, 49707, 49662, 47019, 49747)
improve detectability of deleted pods
**What this PR does / why we need it**:
Adds comment to `waitForPodTerminatedInNamespace` to better explain how it's implemented.
~~It improves pod deletion detection in the e2e framework as follows:~~
~~1. the `waitForPodTerminatedInNamespace` func looks for pod.Status.Phase == _PodFailed_ or _PodSucceeded_ since both values imply that all containers have terminated.~~
~~2. the `waitForPodTerminatedInNamespace` func also ignores the pod's Reason if the passed-in `reason` parm is "". Reason is not really relevant to the pod being deleted or not, but if the caller passes a non-blank `reason` then it will be lower-cased, de-blanked and compared to the pod's Reason (also lower-cased and de-blanked). The idea is to make Reason checking more flexible and to prevent a pod from being considered running when all of its containers have terminated just because of a Reason mis-match.~~
Releated to pr [49597](https://github.com/kubernetes/kubernetes/pull/49597) and issue [49529](https://github.com/kubernetes/kubernetes/issues/49529).
**Release note**:
```release-note
NONE
```
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