Automatic merge from submit-queue (batch tested with PRs 50094, 48966, 49478, 50593, 49140)
Migrate sig-auth e2e tests.
**What this PR does / why we need it:** This PR adds [sig-auth] prefix to
workload e2e tests in accord to requirements of adding a SIG dashboard
to testgrid. Refer PR #48781 for guidelines.
**Release note**:
```release-note
```