Move JNI_OnLoad to separate file which registers both fbjni and jni methods

Summary: Move JNI_ONLoad to a separate file so that both fbjni native methods and vanillla jni native methods can be initialized correctly

Reviewed By: amir-shalem

Differential Revision: D17840166

fbshipit-source-id: 045df0df7a95bc331cbbefb3a118a349f3029465

java/jni/yogajni.cpp

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#include "yogajni.h"
+#include "YGJNIVanilla.h"
+#include <fbjni/fbjni.h>
+#include "common.h"
+
+using namespace facebook::jni;
+using namespace facebook::yoga;
+
+jint JNI_OnLoad(JavaVM* vm, void*) {
+  jint ret = YGJNI::registerNativeMethods(vm);
+
+  JNIEnv* env;
+  vanillajni::ensureInitialized(&env, vm);
+  YGJNIVanilla::registerNatives(env);
+  return ret;
+}