
AudioMixingUtil#mix handles input & output in float or Int16 PCM. Given Float and Int16 use different sample ratnes, this util handles conversion between the two, based on the encoding being mixed to. Migrate AudioMixer to use the util, removing AudioMixingAlgorithm interface and implementation. ChannelMixingAudioProcessor will be migrated after additional performance checks. PiperOrigin-RevId: 548994584