message: Add Java annotations to setMorphWeights.
  Noticed this while working on javadoc stuff.
diff: @@ -19,6 +19,7 @@ package com.google.android.filament;
  import android.support.annotation.IntRange;
  import android.support.annotation.NonNull;
  import android.support.annotation.Nullable;
  +import android.support.annotation.Size;
  import java.nio.Buffer;
  import java.nio.BufferOverflowException;
  @@ -231,7 +232,7 @@ public class RenderableManager {
  }
  }
  - public void setMorphWeights(@EntityInstance int i, float[] weights) {
  + public void setMorphWeights(@EntityInstance int i, @NonNull @Size(min = 4) float[] weights) {
  nSetMorphWeights(mNativeObject, i, weights);
  }
  