Low-frequency "thump" in MASA format using bitrate switching and output to MONO
# Basic info
<!--- Add commit SHA used to reproduce -->
- Encoder (float): d18cbee34
- Decoder: 10b97f38
# Bug description
There is an audible "thump" in latter part of short MASA test vector `stv2MASA2TC48c` when using attached rate switching profile and rendering to MONO output. Here is a diff plot between BASOP and ivas-float-update:
# Ways to reproduce
Use the switching profile [generic_start_13k2_20frames.bin](/uploads/529174f46529ec934532b85308641812/generic_start_13k2_20frames.bin)
with commands
```
./IVAS_cod -q -masa 2 scripts/testv/stv2MASA2TC48c.met -max_band fb generic_start_13k2_20frames.bin 48 scripts/testv/stv2MASA2TC48c.wav test.bs
./IVAS_dec -q MONO 48 test.bs out.wav
```
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issue