persistent volume claim is unable to mount on the pod

Question

I have setup a GKE cluster anad enabled the FileStore CSI driver. I have created the below StorageClass, PersistentVolumeClaim and the Deployment configuration

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: filestore-sc
provisioner: filestore.csi.storage.gke.io
volumeBindingMode: Immediate
allowVolumeExpansion: true
parameters:
  tier: standard
  network: default

kubectl apply -f <storage-class>.yaml

filestore-sc filestore.csi.storage.gke.io Delete Immediate true 17m

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: fileserver
spec:
  accessModes:
  - ReadWriteMany
  storageClassName: filestore-sc
  resources:
    requests:
      storage: 1Ti

kubectl apply -f <pvc.yaml>

NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE fileserver Bound pvc-214e64b5-a28c-4d30-9e23-ba08fbed1482 1Ti RWX filestore-sc 17m

apiVersion: apps/v1
kind: Deployment
metadata:
  name: reader
spec:
  replicas: 1
  selector:
    matchLabels:
      app: reader
  template:
    metadata:
      labels:
        app: reader
    spec:
      containers:
      - name: nginx
        image: nginx:stable-alpine
        ports:
        - containerPort: 80
        volumeMounts:
        - name: fileserver
          mountPath: /usr/share/nginx/html # the shared directory 
          readOnly: true
      volumes:
      - name: fileserver
        persistentVolumeClaim:
          claimName: fileserver

kubectl get pods NAME READY STATUS RESTARTS AGE reader-5c9cf696f-clgkm 0/1 ContainerCreating 0 15m

kubectl describe po reader-5c9cf696f-clgkm

Events:
  Type     Reason       Age                From               Message
  ----     ------       ----               ----               -------
  Normal   Scheduled    16m                default-scheduler  Successfully assigned default/reader-5c9cf696f-clgkm to gke-primary-general-effdaa23-xqqt
  Warning  FailedMount  13m (x6 over 14m)  kubelet            MountVolume.MountDevice failed for volume "pvc-214e64b5-a28c-4d30-9e23-ba08fbed1482" : rpc error: code = Aborted desc = An operation with the given volume key modeInstance/us-central1-a/pvc-214e64b5-a28c-4d30-9e23-ba08fbed1482/vol1 already exists.
 --- Most likely a long process is still running to completion. Retrying.
  Warning  FailedMount  34s (x7 over 14m)  kubelet  Unable to attach or mount volumes: unmounted volumes=[fileserver], unattached volumes=[], failed to process volumes=[]: timed out waiting for the condition
  Warning  FailedMount  2s (x5 over 14m)   kubelet  MountVolume.MountDevice failed for volume "pvc-214e64b5-a28c-4d30-9e23-ba08fbed1482" : rpc error: code = DeadlineExceeded desc = context deadline exceeded

Where am I going wrong? I am following this guide Link