Merge pull request kubernetes#55744 from dashpole/update_cadvisor_v0.…

…25.1

Automatic merge from submit-queue.

Update cadvisor godeps to v0.25.1

**What this PR does / why we need it**:
Update cAdvisor godeps to v0.25.1.
This adds support for the docker overlay2 storage driver.

**Special notes for your reviewer**:
I cherrypicked two commits which add overlay2 support back to cAdvisor's v0.25 branch, which corresponds to k8s v1.6.  This PR effectively cherrypicks those two PRs: google/cadvisor#1803

**Release note**:
```release-note
Bump cAdvisor to v0.25.1, which adds support for the Docker overlay2 storage driver.
```

/sig node
/kind feature
 cc @dchen1107 @abgworrall @yujuhong