Add standalone factory classes which generate YogaNode + YogaConfig

Summary:
Add standalone factory classes which generate YogaNode + YogaConfig, later on it will allow us to separate the yoga interface and actual implementation buck targets (see D17266406)

We've done such breakage change previously in D14122974.

Reviewed By: SidharthGuglani

Differential Revision: D17258196

fbshipit-source-id: b12f1a0d23c3f82b14cee0731a1daf1c015ee32c

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

@@ -0,0 +1,7 @@
+package com.facebook.yoga;
+
+public abstract class YogaConfigFactory {
+  public static YogaConfig create() {
+    return new YogaConfig();
+  }
+}

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

@@ -0,0 +1,11 @@
+package com.facebook.yoga;
+
+public abstract class YogaNodeFactory {
+  public static YogaNode create() {
+    return new YogaNodeJNIFinalizer();
+  }
+
+  public static YogaNode create(YogaConfig config) {
+    return new YogaNodeJNIFinalizer(config);
+  }
+}