Automatic merge from submit-queue (batch tested with PRs 64142, 64426, 62910, 63942, 64548). 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>.

Clean up fake mounters.

**What this PR does / why we need it**:

Fixes https://github.com/kubernetes/kubernetes/issues/61502

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #

**Special notes for your reviewer**:

list of fake mounters:

- (keep) pkg/util/mount.FakeMounter
- (removed) pkg/kubelet/cm.fakeMountInterface:
- (inherit from mount.FakeMounter) pkg/util/mount.fakeMounter
- (inherit from mount.FakeMounter) pkg/util/removeall.fakeMounter
- (removed) pkg/volume/host_path.fakeFileTypeChecker

**Release note**:

```release-note
NONE
```