alsa_sound: fix for out-of-order deadlock in AudioSessionOut

-standby() and setParameters() acquire lock and parent locks in
 out-of-order fashion.
-Moved lock acquisition in standby() after flush() call which
 fixes the order and aligns it as in setParameters()

Change-Id: I0d1ad3d4b0cbf818a6fa2844024cd62aa882de22
CRs-Fixed: 514367, 518682
(cherry picked from commit 21ed4009199637a67419dc36131c68d44af5eb95)
alsa_sound: Allow dual-mic device to be used for VOIP calls

Change-Id: I7a4a79a1c48bd082be8d5163fa8978bca4421390