Automatic merge from submit-queue (batch tested with PRs 53575, 53794). 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>.
Add e2e test case for downward API exposing pod UID
**What this PR does / why we need it**:
Pod UID is added to downward API env var in #48125 for 1.8. This PR adds a e2e test case for it.
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #
ref: #48125
**Special notes for your reviewer**:
**Release note**:
```release-note
NONE
```
Automatic merge from submit-queue (batch tested with PRs 53507, 53772, 52903, 53543). 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>.
Split downward API e2e test case for pod/host IP into two
**What this PR does / why we need it**:
Split the test case in order to avoid version block pod IP e2e test.
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #
ref: https://github.com/kubernetes/kubernetes/pull/42717#discussion_r144026427
**Special notes for your reviewer**:
/cc @timothysc @andrewsykim
