osmux: Make sure RTP AMR feed to osmux is in octet-aligned mode

The Osmux implementation in libosmo-netif expects to work with RTP AMR
in octet-aligned mode. Therefore, if the peer connection received RTP
AMR in bandwidth-efficient mode, we need to convert it to octet-aligned
before feeding the packets to the osmux layer.

Related: SYS#6161
Change-Id: Ifeec44241079f7a31da12745c92bfdc4fb222f3a
3 files changed