daemon: manage properly hold on and hold off

Status:

* Hold on/off from Ring account work fine
* Hold on from polycom works fine
* Hold off from polycom does not restart the stream
  - Hold off lead to a re-invite (switch from PCMA to G722)
  - codec selection from PCMA to G722 is correct
  - Libav encoder switch correctly to G722
  - Libav decoder blocks in av_codec_find_stream_info

Refs #67275

Change-Id: I9c95cdb6e35934583702d9ae697926283251e5ac