Renderer configuration error in IVAS_dec and IVAS_rend

There is a mismatch between the IVAS_dec and IVAS_rend for the renderer directivity configuration, but they are both wrong.

• In IVAS_dec, the directivity attenuation is correctly set up for the first subframe, but is unintentionally overwritten with the last configuration for the next subframe. This setting is effectively used for all subframes except the very first.
• In IVAS_rend, there is a renderer instance allocated per source, which means each renderer instance uses the first configuration.

So, IVAS_dec uses the last configuration and IVAS_rend will use the first. The configuration was verified with ISM1 where this gives a correct result by accident.