AudioFlinger: remove float and multichannel shim for AIDL

Test: Validate AudioEffects with AIDL mode on and off.
Test: atest android.media.audio.cts.AudioEffectTest \
  android.media.audio.cts.AudioPreProcessingTest \
  android.media.audio.cts.BassBoostTest \
  android.media.audio.cts.EnvReverbTest \
  android.media.audio.cts.EqualizerTest \
  android.media.audio.cts.LoudnessEnhancerTest \
  android.media.audio.cts.PresetReverbTest \
  android.media.audio.cts.VirtualizerTest \
  android.media.audio.cts.VisualizerTest
Bug: 282066693
Change-Id: I08ab707f56d4e7c445306dc1532e887bbbb276c7