Permission denied when write data to mounted gcp filestore volume instance

This is a clone of issue OCPBUGS-512. The following is the description of the original issue:
—
Description of problem:

Permission denied when write data to mounted gcp filestore volume instance

Version-Release number of selected component (if applicable):

gcp-filestore-csi-driver-operator.v4.12.0

How reproducible:

Always

Steps to Reproduce:1.
2.Deploy gcp filestore csi driver operator
3.Deploy gcp fiestore csi driver 

apiVersion: operator.openshift.io/v1
kind: ClusterCSIDriver
metadata:
    name: filestore.csi.storage.gke.io
spec:
  managementState: Managed
  fsGroupPolicy: File

3.Create pvc/pod

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: myclaim2
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 2Gi
  storageClassName: 'filestore-example2'

4.oc rsh pod

sh-4.4$ touch test
touch: cannot touch 'test': Permission denied
sh-4.4$ id
uid=1000670000(1000670000) gid=0(root) groups=0(root),1000670000
sh-4.4$ ls -lZ /tmp1
total 16
drwx------. 2 root root system_u:object_r:nfs_t:s0 16384 Aug 24 06:16 lost+found

5.Found that csidriver .spec.fsGroupPolicy is ReadWriteOnceWithFSType

oc get csidriver/filestore.csi.storage.gke.io -o yaml
apiVersion: storage.k8s.io/v1
kind: CSIDriver
metadata:
  annotations:
    csi.openshift.io/managed: "true"
    operator.openshift.io/spec-hash: 998642f0945b32fa885ab52b567c19b50b957e3628ad1dd0e6280d67913b03f5
  creationTimestamp: "2022-08-24T03:20:52Z"
  name: filestore.csi.storage.gke.io
  resourceVersion: "57160"
  uid: 17a75a4d-89db-4ad6-939e-2965055277bb
spec:
  attachRequired: false
  fsGroupPolicy: ReadWriteOnceWithFSType
  podInfoOnMount: true
  requiresRepublish: false
  storageCapacity: false
  volumeLifecycleModes:
  - Persistent

Actual results:

1. csidriver .spec.fsGroupPolicy is still default value
2. No root user does not have the write/exec permission after mounted the volume instance.

Expected results:

Additional info: