[Fabric] Adds ActivityIndicator animating property (#12124)

* add Fabric ActivityIndicator animating property

* Change files

Author: TatianaKapos

change/react-native-windows-3f4b160f-4cfd-46cf-9d96-fe93592551af.json

@@ -0,0 +1,7 @@
+{
+  "type": "prerelease",
+  "comment": "add Fabric ActivityIndicator animating property",
+  "packageName": "react-native-windows",
+  "email": "tatianakapos@microsoft.com",
+  "dependentChangeType": "patch"
+}

vnext/Microsoft.ReactNative/Fabric/Composition/ActivityIndicatorComponentView.cpp

@@ -57,6 +57,10 @@ void ActivityIndicatorComponentView::updateProps(
     m_ActivityIndicatorVisual.updateColor(newViewProps->color.AsWindowsColor());
   }
 
+  if (newViewProps->animating != oldViewProps->animating) {
+    m_ActivityIndicatorVisual.IsVisible(newViewProps->animating);
+  }
+
   updateBorderProps(*oldViewProps, *newViewProps);
   m_props = std::static_pointer_cast<facebook::react::ViewProps const>(props);
 }