Automatic merge from submit-queue. 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>.
Combine downward api e2e test cases.
**What this PR does / why we need it**:
This will reduce one loop of create/delete pod. Hope it can save some test time.
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #
**Special notes for your reviewer**:
**Release note**:
```release-note
NONE
```
This test creates a golden list of existing conformance tests. Efforts
to add or remove conformance tests will require you to rebuild the
golden list, and changes to the golden list will be reviewed by
sig-architecture.
