Addressed using k8s client APIs to fetch secrets

Based on the review comments addressed the following,
- Moved away from having to update the pod with volumes
when a new Ceph cluster is added for provisioning via the
CSI driver

- The above now used k8s APIs to fetch secrets
  - TBD: Need to add a watch mechanisim such that these
secrets can be cached and updated when changed

- Folded the Cephc configuration and ID/key config map
and secrets into a single secret

- Provided the ability to read the same config via mapped
or created files within the pod

Tests:
- Ran PV creation/deletion/attach/use using new scheme
StorageClass
- Ran PV creation/deletion/attach/use using older scheme
to ensure nothing is broken
- Did not execute snapshot related tests

Signed-off-by: ShyamsundarR <srangana@redhat.com>

examples/rbd/template-csi-rbdplugin-patch.yaml

@@ -12,22 +12,10 @@ spec:
       containers:
         - name: csi-rbdplugin
           volumeMounts:
-            - name: provisioner-secret-<cluster-fsid>
-              mountPath: "/etc/ceph-cluster-<cluster-fsid>-provisioner-secret"
-              readOnly: true
-            - name: publish-secret-<cluster-fsid>
-              mountPath: "/etc/ceph-cluster-<cluster-fsid>-publish-secret"
-              readOnly: true
             - name: ceph-cluster-<cluster-fsid>
-              mountPath: "/etc/ceph-cluster-<cluster-fsid>/"
+              mountPath: "/etc/csi-config/ceph-cluster-<cluster-fsid>"
               readOnly: true
       volumes:
-        - name: provisioner-secret-<cluster-fsid>
-          secret:
-            secretName: ceph-cluster-<cluster-fsid>-provisioner-secret
-        - name: publish-secret-<cluster-fsid>
-          secret:
-            secretName: ceph-cluster-<cluster-fsid>-publish-secret
         - name: ceph-cluster-<cluster-fsid>
-          configMap:
-            name: ceph-cluster-<cluster-fsid>
+          secret:
+            secretName: ceph-cluster-<cluster-fsid>