fusion3: get reboot reason from cmdline

Change-Id: I1731d00c850aef0f20320071f686c1c0b4a43510
fusion3: Use legacy CAF input buffersize logic for audio

Older CAF audio HALs only used getInputBufferSize for 5.1 audio,
and our CAF tag is such a HAL.  Use the legacy logic to permit
audio recording to work.

Change-Id: I61a3321d7b91d9ac47f252f0f90d15be5b82ab4e