[non-BE] Resolve "ASAN: SBA DTX bitrate switching decoding"

• Related issues: #1087 (closed)
• Requested reviewers: @fotopoulou

Reason why this change is needed

• Crash in SBA DTX bitrate switching decoding

Description of the change

• Extend the length of the buffer for MCT decoding to avoid out-of-bound writing.

Affected operating points

• Not BE in SID to MCT switching frames. Differences are negligible.