All devices do not have to support AV1 decode. Send the AV1 stream to AV1-capable, fallback to AVC. Previously, there could be AV1 > HEVC > AVC priorities set

All devices do not have to support AV1 decode. Send the AV1 stream to AV1-capable, fallback to AVC. Previously, there could be AV1 > HEVC > AVC priorities set up, after this only AV1 > AVC.