BluetoothAudio: Refine the FMQ size for A2DP software encoding

For those high-resolution codecs, they are 24 or 32 bits per sample, so
the buffer size must be the LCM of 16, 24, and 32.

Bug: 194980528
Test: A2DP playing with aptX and / or LDAC
Change-Id: I788e185496dea4a1b40fa369e032a4f8491b835b
Merged-In: I788e185496dea4a1b40fa369e032a4f8491b835b
(cherry picked from commit a0cc2473)