Merge "EffectDownmix: Remove obsolete define" am: a4c95a851c am: fe2a40564c am: 5aa9f2cf57 am: d6d5e45b95

Original change: https://android-review.googlesource.com/c/platform/frameworks/av/+/1700168

Change-Id: Id3054952c5c752b3dd29526d19281f150bddd5c2