OMASA 1SEP object encoding has wrong transport mix

Basic info

• Commit SHA: main
• Platform: all

Bug description

With OMASA, in ISM_MASA_MODE_MASA_ONE_OBJ mode encoding, the first object is panned to the transport audio signal mix using a wrong direction (the direction of the separated object instead of its own direction). As a result, the direction of the first object in the transport audio signals is wrong, and it deteriorates the quality of the rendering.

Ways to reproduce

Use OMASA on bitrate where ISM_MASA_MODE_MASA_ONE_OBJ is used.