[non-BE] Keep TSM memory in JBM bitrate switching

• Related issues: #1324 (closed)
• Requested reviewers:

Reason why this change is needed

• TSM memory is lost in JBM bitrate switching.

Description of the change

• Keep the TSM memory in JBM bitrate switching.

Affected operating points

• Non-BE in JBM and bitrate switching when the number of internal channels is changing.
• Subjective improvement is observed for BINAURAL outputs when switching between bitrates with the same number of TCs but with the TD decorrelator on and off, typically in MASA.
• Other operating points have limited subjective impact - though the synthesis is improved, switching artifacts coming from a change of the number of TCs are dominant.