Automatic merge from submit-queue

Support persistent volume usage for kubernetes running on Photon Controller platform

**What this PR does / why we need it:**
Enable the persistent volume usage for kubernetes running on Photon platform.
Photon Controller: https://vmware.github.io/photon-controller/

_Only the first commit include the real code change.
The following commits are for third-party vendor dependency and auto-generated code/docs updating._

Two components are added:
pkg/cloudprovider/providers/photon: support Photon Controller as cloud provider
pkg/volume/photon_pd: support Photon persistent disk as volume source for persistent volume

Usage introduction:
a. Photon Controller is supported as cloud provider.
When choosing to use photon controller as a cloud provider, "--cloud-provider=photon --cloud-config=[path_to_config_file]" is required for kubelet/kube-controller-manager/kube-apiserver. The config file of Photon Controller should follow the following usage:

```
[Global]
target = http://[photon_controller_endpoint_IP]
ignoreCertificate = true
tenant = [tenant_name]
project = [project_name]
overrideIP = true
```

b. Photon persistent disk is supported as volume source/persistent volume source.
yaml usage:

```
volumes:
  - name: photon-storage-1
    photonPersistentDisk:
        pdID: "643ed4e2-3fcc-482b-96d0-12ff6cab2a69"
```
pdID is the persistent disk ID from Photon Controller.

c. Enable Photon Controller as volume provisioner.
yaml usage:

```
kind: StorageClass
apiVersion: storage.k8s.io/v1beta1
metadata:
  name: gold_sc
provisioner: kubernetes.io/photon-pd
parameters:
  flavor: persistent-disk-gold
```

The flavor "persistent-disk-gold" needs to be created by Photon platform admin before hand.