Misleading combination of LassiOption.CAMERA_AND_GALLERY and MediaType.PHOTO_VIDEO_PICKER

The following is misleading and should probably throw:

```kt
lassi.with(LassiOption.CAMERA_AND_GALLERY)
       .setMediaType(MediaType.PHOTO_VIDEO_PICKER)
```

The `CAMERA` part has no effect when using `PHOTO_VIDEO_PICKER`. I think it would be great of you could at least mention it in the docs somewhere. And the example code should not have an invalid invocation.
