Cleanup csi.openstorage.org parameters after adding to VolumeLabels

[ggriffiths]

Signed-off-by: Grant Griffiths [email protected]

What this PR does / why we need it:
We were leaving csi.openstorage.org parameters around in locator.VolumeLabels. This is not needed, as we copy these fields directly. These fields are only needed for transporting these values from the our external-provisioner fork to our CSI Driver.

See this example of the existing behavior. Each pvc.Label occurs twice. Once in the csi.openstorage.org/pvc-labels field, and once as it's own field.

csi.openstorage.org/pvc-labels={"app":"minio"
    "chart":"minio-3.0.1",
    "heritage":"Helm",
    "release":"minio-reliability",
},
csi.openstorage.org/pvc-name=minio-reliability,
csi.openstorage.org/pvc-namespace=minio,
csi.openstorage.org/pvc-annotations={"volume.beta.kubernetes.io/storage-provisioner":"pxd.portworx.com"},
namespace=minio,
pvc=minio-reliability,
release=minio-reliability,
app=minio,
chart=minio-3.0.1,
heritage=Helm

Which issue(s) this PR fixes (optional)
Closes #

Special notes for your reviewer:

[ggriffiths]

Before, we were leaving around a bunch of metadata. Cleaned this up, see below.

tested - results:

[grant@PDC4-SM26-N8 examples]$ cat pvc.yaml 
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: no-auth-mysql-data
  annotations:
    volume.beta.kubernetes.io/storage-class: portworx-sc
  labels:
    abc: "456"
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 2Gi
[root@grant-k8s-node0 /]# /opt/pwx/bin/pxctl v i 116151127435958097
Volume  :  116151127435958097
        Name                     :  pvc-4385a0c9-9b12-4bf2-921b-9dca657044e8
        Size                     :  2.0 GiB
        Format                   :  ext4
        HA                       :  1
        IO Priority              :  HIGH
        Creation time            :  Feb 25 23:21:10 UTC 2020
        Shared                   :  no
        Status                   :  up
        State                    :  detached
        Labels                   :  abc=456,namespace=default,pvc=no-auth-mysql-data

[harsh-px]

LGTM