[non-BE] Resolve "Noise Bursts in SBA at 32 kbps with FER"
Related to #565 (closed), solving bug in frame erasure for SBA, where the initialisation of total_brate was wrong and 2 other conditions needed correction for inactive content
Related to #565 (closed), solving bug in frame erasure for SBA, where the initialisation of total_brate was wrong and 2 other conditions needed correction for inactive content