How to set the shutter time but leave the ISO (sensitivity) on auto on android

I am building an Android app with the Camera2 API that uses short shutter times, 1/1000 and 1/2000.
I can set the SENSOR_EXPOSURE_TIME without any problem. But I want to keep the ISO (SENSOR_SENSITIVITY) on auto mode.


To set the shutter speed I use the following code:
mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_OFF);
mPreviewRequestBuilder.set(CaptureRequest.SENSOR_EXPOSURE_TIME, EXPOSURE);
mCaptureSession.setRepeatingRequest(mPreviewRequestBuilder.build(), null, surfaceView.getmBackgroundHandler());



This code works OK, but because the CONTROL_AE_MODE is set to CONTROL_AE_MODE_OFF the ISO (SENSOR_SENSITIVITY) has to be set manually also. And this is what I don't want, I want to keep the ISO on auto.


Is there any way to accomplish this or is there a workaround?