Automatic merge from submit-queue (batch tested with PRs 60197, 61614, 62074, 62071, 62301). 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>.

Adds e2e test for vpxd restart scenario in vSphere Cloud Provider

This PR adds a test to verify Volume access in a situation where VMware vCenter's `vpxd` service is down. The test mainly verifies Volume/file access before, during, and after restarting the `vpxd` service on the vCenter host.

See vmware/kubernetes#373 for more details.

**Reviewers note:** This PR was internally reviewed at vmware/kubernetes#468.

/cc @kubernetes/vmware