Fraunhofer's downmixer has additional buffering, this is incompatible
with how DownmixerBufferProvider used to process incomplete buffers.
Now the effects HIDL wrapper delivers frameCount updates in
audiobuffers to the server side. This fixes playback of multichannel
sound streams.
Bug: 36181621
Test: play 5.1 track from Play Music
Change-Id: Iffe3327c6eedef85151eec2b41e0aedfb7ffa6dc
Result: no hwbinder calls due music processing.
Added IEffect.close method for explicitly freeing up of resources
consumed by the effect before automatic server objects reaping
gets to it.
Added IEffect.setProcessBuffers method for updating the input /
output buffers on the go.
Test: make, use Play Music with effects, check traces
Bug: 30222631
Change-Id: Ia1e1bc7098fab59aa970e0ce4acdb48007409644