Automatic merge from submit-queue (batch tested with PRs 52767, 55065, 55148, 56228, 56221). 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>.
Add resize support for ceph RBD
Add resize support for ceph RBD
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: part of [#657](https://github.com/kubernetes/community/pull/657)
**Special notes for your reviewer**:
**Release note**:
```release-note
Add resize support for ceph RBD
```
WIP, need to add fs resize,
assign to myself first
/assign @NickrenREN
Introduce feature gate for expanding PVs
Add a field to SC
Add new Conditions and feature tag pvc update
Add tests for size update via feature gate
register the resize admission plugin
Update golint failures