Hammerhead - Reduce mic gain for video chat use case

Added new path for mic with AEC in speakerphone mode
for voice/video chat use case and reduced gain by 9 dB.

Bug: 13279002.

Change-Id: Ief801c1c891b6b076a8713fae9516134abd05929
Signed-off-by: MURA Stefano [STELIX PippoX3] <ssspinni@gmail.com>