This CL adds `SonicTest` and `RandomParameterizedSonicTest` as
initial basic unit testing for `Sonic.java`. The tested scenarios
do not necessarily verify a correct implementation of Sonic, but rather
hope to catch any behaviour change from the current implementation.
The change includes a small fix for a lossy simplification and also
checks whether the output sample count matches the expected drift from
the truncation accumulation error present in Sonic's resampler. This is
important as pre-work for fixing issues with unexpected durations within
`SonicAudioProcessor` and `SpeedChangingAudioProcessor` that cause AV
sync issues for speed changing effects.
This is a partial roll forward of e88d6fe459, which was rolled back in
873d485056.
PiperOrigin-RevId: 677756854
3d3ec85c12