added flag for useBatchingForLayoutOutputs experiment

Summary:
Using a config flag to switch between different implementations of transferring layout outputs
- YogaNodeJNI uses multiple access of java fields to pass all properties like width, height, margin etc...
- YogaNodeJNIBatching uses a float array to pass all the data in one java field access

Reviewed By: davidaurelio

Differential Revision: D14378301

fbshipit-source-id: 0da5b28e6a67ad8fd60eb7efe622d9b2deaf177f

ReactAndroid/src/main/java/com/facebook/yoga/YogaNode.java

@@ -10,11 +10,11 @@ import javax.annotation.Nullable;
 
 public abstract class YogaNode {
   public static YogaNode create() {
-    return new YogaNodeJNI();
+    return YogaConfig.useBatchingForLayoutOutputs ? new YogaNodeJNIBatching() : new YogaNodeJNI();
   }
 
   public static YogaNode create(YogaConfig config) {
-    return new YogaNodeJNI(config);
+    return YogaConfig.useBatchingForLayoutOutputs ? new YogaNodeJNIBatching(config) : new YogaNodeJNI(config);
   }
 
   public abstract void reset();