Automatic merge from submit-queue (batch tested with PRs 64226, 65880). 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>.

Populate NodeAffinity on top of labels for cloud based PersistentVolumes

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

This PR populates the NodeAffinity field (on top of the existing labels) for PVs backed by cloud providers like EC2 EBS and GCE PD.

**Special notes for your reviewer**:
Related to https://github.com/kubernetes/kubernetes/pull/63232

Sample `describe pv` output for EBS with node affinity field populated:
```
kubectl describe pv pv0001
Name:              pv0001
Labels:            failure-domain.beta.kubernetes.io/region=us-west-2
                   failure-domain.beta.kubernetes.io/zone=us-west-2a
Annotations:       <none>
Finalizers:        [kubernetes.io/pv-protection]
StorageClass:      
Status:            Available
Claim:             
Reclaim Policy:    Retain
Access Modes:      RWO
Capacity:          5Gi
Node Affinity:     
  Required Terms:  
    Term 0:        failure-domain.beta.kubernetes.io/zone in [us-west-2a]
                   failure-domain.beta.kubernetes.io/region in [us-west-2]
Message:           
Source:
    Type:       AWSElasticBlockStore (a Persistent Disk resource in AWS)
    VolumeID:   vol-00cf03a068c62cbe6
    FSType:     ext4
    Partition:  0
    ReadOnly:   false
Events:         <none>
```

/sig storage
/assign @msau42

**Release note**:
```NONE```