Expose ReactAndroid/src/main/jni/react/cxxcomponents via prefab

Summary:
Reference reactwg/react-native-releases#41 (reply in thread)
I'm exposing `ReactAndroid/src/main/jni/react/cxxcomponents` to be consumed via prefab.
It will be available to both: `react_nativemodule_core` and `reactnativejni`

Changelog:
[Internal] [Changed] - Expose ReactAndroid/src/main/jni/react/cxxcomponents via prefab

Differential Revision: D41965512

fbshipit-source-id: afbeccec4b70de3f5296e0a81240ea9073ea8a6b

ReactAndroid/build.gradle

@@ -117,7 +117,10 @@ final def preparePrefab = tasks.register("preparePrefab", PreparePrefabHeadersTa
             ),
             new PrefabPreprocessingEntry(
                 "fabricjni",
-                new Pair("src/main/jni/react/fabric", "")
+                [
+                    new Pair("src/main/jni/react/fabric", ""),
+                    new Pair("src/main/jni/react/cxxcomponents", "react/cxxcomponents/")
+                ]
             ),
             new PrefabPreprocessingEntry(
                 "react_render_mapbuffer",
@@ -206,7 +209,10 @@ final def preparePrefab = tasks.register("preparePrefab", PreparePrefabHeadersTa
             ),
             new PrefabPreprocessingEntry(
                 "reactnativejni",
-                new Pair("src/main/jni/react/jni", "react/jni/"),
+                [
+                    new Pair("src/main/jni/react/jni", "react/jni/"),
+                    new Pair("../ReactCommon/cxxreact/", "cxxreact/"),
+                ]
             ),
         ]
     )