Unused heap in OMASA

Some parts of heap memory is unused in OMASA, Disc mode:

encoder for MASA + 4ISMs at 48 kHz:

ivas_masa_enc_open() 229 malloc sizeof( OMASA_ENCODER_DATA_STATE ) 3848 bytes

decoder, binaural output at 48 kHz:

ivas_omasa_separate_object_renderer_open() 370 malloc sizeof( ISM_RENDERER_DATA ) 520 bytes

ivas_omasa_separate_object_renderer_open() 382 malloc sizeof( float ) * init_interpolator_length 960 bytes