Update modal wrapper to be translatable to TypeScript (#49923)

Summary:
Pull Request resolved: #49923

Changelog: [Internal]

Reviewed By: huntie

Differential Revision: D70887822

fbshipit-source-id: 729e91245cfb750cf1de4f4532925ff7263b3d82

Author: j-piasecki

packages/react-native/Libraries/Modal/Modal.js

@@ -362,14 +362,18 @@ const styles = StyleSheet.create({
   },
 });
 
+type ModalRefProps = $ReadOnly<{
+  ref?: React.RefSetter<PublicModalInstance>,
+}>;
+
 // NOTE: This wrapper component is necessary because `Modal` is a class
 // component and we need to map `ref` to a differently named prop. This can be
 // removed when `Modal` is a functional component.
 function Wrapper({
   ref,
   ...props
 }: {
-  ref?: React.RefSetter<PublicModalInstance>,
+  ...ModalRefProps,
   ...ModalProps,
 }): React.Node {
   return <Modal {...props} modalRef={ref} />;

packages/react-native/Libraries/__tests__/__snapshots__/public-api-test.js.snap

@@ -5985,10 +5985,10 @@ export type ModalProps = {
   ...ModalPropsAndroid,
   ...ViewProps,
 };
-declare function Wrapper({
+type ModalRefProps = $ReadOnly<{
   ref?: React.RefSetter<PublicModalInstance>,
-  ...ModalProps,
-}): React.Node;
+}>;
+declare function Wrapper({ ...ModalRefProps, ...ModalProps }): React.Node;
 declare export default typeof Wrapper;
 "
 `;