ISAR post-renderer broken for externally rendered OMASA input and BINAURAL_SPLIT_CODED format
# Basic info
- Float reference:
- Encoder (float): d62f976a025fe8494a38edebf9407cda075415ad
- Decoder (float): d62f976a025fe8494a38edebf9407cda075415ad
- Fixed point:
- Encoder (fixed): c145188515312eab96d1de6b7a921bfc5fe402d8
- Decoder (fixed): c145188515312eab96d1de6b7a921bfc5fe402d8
# Bug description
Running external renderer with OMASA input and BINAURAL_SPLIT_CODED output followed by ISAR post-renderer produces garbage.

# Ways to reproduce
```
./IVAS_rend -fs 48 -render_config tests/split_rendering/renderer_configs/split_renderer_config_0dof_768k_default.txt -i scripts/testv/stvOMASA_4ISM_2MASA2TC48c_cut.wav -if ISM4MASA2 -im scripts/testv/stvISM1.csv scripts/testv/stvISM2.csv scripts/testv/stvISM3.csv scripts/testv/stvISM4.csv scripts/testv/stvOMASA_4ISM_2MASA2TC48c.met -o splt.bit -of BINAURAL_SPLIT_CODED -T scripts/trajectories/rotate_euler_quaternion_30s_delayed.csv -fr 20
./ISAR_post_rend -fs 48 -i splt.bit -if BINAURAL_SPLIT_CODED -o syn.wav -T scripts/trajectories/rotate_euler_quaternion_30s.csv -fr 20
```
issue