Call recording encoder/format choice 3/3

Adds a user option between WB AMR (the default) or
HE-AAC for the encoding of call recording audio.
Also changes the output format of the file appropriately
(WB AMR now uses the WB_AMR output format and HE_AAC chooses
the MPEG_4 output. File extensions are adjust accordingly as well).
This was in reponse to people complaining the quality of call
recording audio is poor. It's noticibly better using HE-AAC,
but filesizes are larger.

Change-Id: Iffcdd3ba6f9aa80e238bbcc5db51809a4721711e