vtkOSPRayVolumeMapper AutoAdjustSampleDistances compatibility with OSPRay v2
Turn on AutoAdjustSampleDistances for vtkOSPRayVolumeMapper. VTK 9.0 with OSPRay v1.85 volume rendering speed up. VTk 9.1 with OSPRay v2.9 volume rendering does not make difference.