message: Animated peek height prop changes
  Won't expose animated as a prop (see if anybody asks for it) and true seems the right default
diff: @@ -18,7 +18,7 @@ public class BottomSheetView extends ViewGroup {
  }
  void setPeekHeight(int peekHeight) {
  - bottomSheetBehavior.setPeekHeight(peekHeight);
  + bottomSheetBehavior.setPeekHeight(peekHeight, true);
  }
  void setExpandedOffset(int expandedOffset) {
  