As per title, the preferred video MIME type(s) don't seem to be used when making adaptive video track selections.

I found this when investigating #9463, where it would have been useful to provide the following as a viable workaround to prefer the H264 adaptation set:

trackSelector.setParameters(
    trackSelector
        .getParameters()
        .buildUpon()
        .setPreferredVideoMimeType(MimeTypes.VIDEO_H264));