Fix the documentation for UiKitView#creationParams (flutter#31619)

It looks like the documentation for UiKitView has been copy-pasted from AndroidView or so.
This PR fixes the word 'Android' to 'iOS' for the `creationParams`.

packages/flutter/lib/src/widgets/platform_view.dart

@@ -232,7 +232,7 @@ class UiKitView extends StatefulWidget {
 
   /// Passed as the `arguments` argument of [-\[FlutterPlatformViewFactory createWithFrame:viewIdentifier:arguments:\]](/objcdoc/Protocols/FlutterPlatformViewFactory.html#/c:objc(pl)FlutterPlatformViewFactory(im)createWithFrame:viewIdentifier:arguments:)
   ///
-  /// This can be used by plugins to pass constructor parameters to the embedded Android view.
+  /// This can be used by plugins to pass constructor parameters to the embedded iOS view.
   final dynamic creationParams;
 
   /// The codec used to encode `creationParams` before sending it to the