Assign orderIndex_ in ConcreteViewShadowNode constructor instead of ViewShadowNode's constructor

Summary:
Changelog: [Internal]

`orderIndex_` was only being assigned for `ViewShadowNode`, not for other `ShadowNodes` that are later represented on the screen.

Reviewed By: shergin

Differential Revision: D20746477

fbshipit-source-id: c04c2cfea14b9141d22bc3d9e9bb4c0c59925754

ReactCommon/fabric/components/view/ConcreteViewShadowNode.h

@@ -52,6 +52,22 @@ class ConcreteViewShadowNode : public ConcreteShadowNode<
       ViewPropsT,
       ViewEventEmitterT,
       Ts...>;
+
+  ConcreteViewShadowNode(
+      ShadowNodeFragment const &fragment,
+      ShadowNodeFamily::Shared const &family,
+      ShadowNodeTraits traits)
+      : BaseShadowNode(fragment, family, traits) {
+    initialize();
+  }
+
+  ConcreteViewShadowNode(
+      ShadowNode const &sourceShadowNode,
+      ShadowNodeFragment const &fragment)
+      : BaseShadowNode(sourceShadowNode, fragment) {
+    initialize();
+  }
+
   using ConcreteViewProps = ViewPropsT;
 
   using BaseShadowNode::BaseShadowNode;
@@ -84,6 +100,11 @@ class ConcreteViewShadowNode : public ConcreteShadowNode<
     return list;
   }
 #endif
+
+ private:
+  void initialize() noexcept {
+    BaseShadowNode::orderIndex_ = BaseShadowNode::getConcreteProps().zIndex;
+  }
 };
 
 } // namespace react

ReactCommon/fabric/components/view/ViewShadowNode.cpp

@@ -39,8 +39,6 @@ static bool isColorMeaningful(SharedColor const &color) noexcept {
 void ViewShadowNode::initialize() noexcept {
   auto &viewProps = static_cast<ViewProps const &>(*props_);
 
-  orderIndex_ = viewProps.zIndex;
-
   bool formsStackingContext = !viewProps.collapsable ||
       viewProps.pointerEvents == PointerEventsMode::None ||
       !viewProps.nativeId.empty() || viewProps.accessible ||