Fabric: Making YogaStylableProps::yogaNode public

Summary:
This is aligned with all simular changes that we do for `*Props` types (see D19583582 and D19390813).

Changelog: [Internal] Fabric-specific internal change.

Reviewed By: sammy-SC

Differential Revision: D19596281

fbshipit-source-id: 283b89c65504e20a461b12c2d1218325c6621dd8

ReactCommon/fabric/components/view/yoga/YogaStylableProps.h

@@ -25,15 +25,12 @@ class YogaStylableProps {
 
 #pragma mark - Props
 
- protected:
-  friend class YogaLayoutableShadowNode;
-  YGStyle const yogaStyle{};
+  YGStyle yogaStyle{};
 
 #if RN_DEBUG_STRING_CONVERTIBLE
 
 #pragma mark - DebugStringConvertible (Partial)
 
- public:
   SharedDebugStringConvertibleList getDebugProps() const;
 
 #endif