Assert in stereo_switching_enc_fx for OMASA rate switching input (new STV)

Basic info

• Fixed point:
  • Encoder (fixed): 028d6837

Bug description

See job here https://forge.3gpp.org/rep/sa4/audio/ivas-basop/-/jobs/621112

There is an assert with new OMASA STV test vector on the BASOP encoder. This is rate switching and the switch happening in the crashing frame 706 is from 80 kbps to 48 kbps at least based on the encoder config structure. Element mode seems to be IVAS_CPE_DFT and last element mode was IVAS_CPE_MDCT.

Ways to reproduce

./IVAS_cod -ism_masa 3 1 ./scripts/testv/stv20sOMASA_3ISM1TC_ISM1.csv ./scripts/testv/stv20sOMASA_3ISM1TC_ISM2.csv ./scripts/testv/stv20sOMASA_3ISM1TC_ISM3.csv ./scripts/testv/stv20sOMASA_3ISM1TC.met ./scripts/switchPaths/sw_13k2_512k_2fr_start_48k_omasatechs_3ism.bin 48 ./scripts/testv/stv20sOMASA_3ISM1TC.wav debug.bit