Screenrecord: allow force mic for audio

Some older devices audio blobs do not support audio submix,
allow those devices to force using the mic for audio while
screenrecording.
https://gerrit.omnirom.org/#/c/6063

Change-Id: I2fa895a1faa431d2b007ff9a0b735b09371999ae
Merge "Screenrecord: allow force mic for audio" into pac-4.4