Automatic merge from submit-queue (batch tested with PRs 64034, 64072, 64146, 64059, 64161). 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>.

e2e: Remove flaky from CSI E2E test

**What this PR does / why we need it**:
The tests have been passing consistently and now we can remove the Flaky tag.

See results here: https://k8s-testgrid.appspot.com/sig-storage#gce-flaky&width=5

**Release note**:

```release-note
NONE
```