C2SoftFlacEnc: Update max input buffer size calculation

INPUT_MAX_BUFFER_SIZE is now set based on channel count and
pcm encoding mode.

Bug: 332051852
Test: atest CtsMediaV2TestCases -- --module-arg  CtsMediaV2TestCases:\
instrumentation-arg:codec-prefix:=c2.android.flac
Change-Id: I9edf56de98e5ad73dd2cbec15f74d04e90f62124
2 files changed