audio: fix STMR test fail on PTCRB

STMR(SideTone Masking Rating) test was fail on PTCRB.
To fix this issue, sidetone is enable and volume is set 51.
It is applied only in case of buitin mic voice call.

bug: 7291594
Change-Id: I519180bc08adb3f06ec232bfabb9fbccbe32e141
Signed-off-by: Iliyan Malchev <malchev@google.com>
1 file changed