Don't export private headers from Buck target (#1269)

Summary:
Pull Request resolved: https://github.com/facebook/yoga/pull/1269

X-link: https://github.com/facebook/react-native/pull/37127

This prevents targets which include Yoga from using its private APIs.

Instances of this have been mostly cleaned up in the past diffs, with the major exception of RN Fabric. To stage this without blocking on that, I added a `yoga-private-api` target for now to keep using these headers while making it unlikely new usages will show up.

Reviewed By: javache

Differential Revision: D45339425

fbshipit-source-id: 9a00c89c4d6ccfa33db7064c34b5cf5d400d58fe

java/jni/YGJTypesVanilla.h

@@ -5,11 +5,13 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-#include "jni.h"
-#include <yoga/YGValue.h>
-#include <yoga/Yoga.h>
 #include <map>
+#include <vector>
+
+#include <yoga/Yoga.h>
+
 #include "common.h"
+#include "jni.h"
 
 class PtrJNodeMapVanilla {
   std::map<YGNodeRef, size_t> ptrsToIdxs_;