code: func dropDisabledVolumeDevicesFields(podSpec, oldPodSpec *api.PodSpec) {
  	if !utilfeature.DefaultFeatureGate.Enabled(features.BlockVolume) && !volumeDevicesInUse(oldPodSpec) {
  		for i := range podSpec.Containers {
  			podSpec.Containers[i].VolumeDevices = nil
  		}
  		for i := range podSpec.InitContainers {
  			podSpec.InitContainers[i].VolumeDevices = nil
  		}
  	}
  }
docs: // dropDisabledVolumeDevicesFields removes disabled fields from []VolumeDevice if it has not been already populated.
  // This should be called from PrepareForCreate/PrepareForUpdate for all resources containing a VolumeDevice