Add C++ Turbo Module enum Event Emitter example (#46049)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/46049

## Changelog:

[General] [Added] - Add C++ Turbo Module enum Event Emitter example

Reviewed By: kentwilliam

Differential Revision: D61336742

fbshipit-source-id: 81ac54020f4d88dc3c1235541d613a59235069a3

packages/rn-tester/js/examples/TurboModule/NativeCxxModuleExampleExample.js

@@ -283,6 +283,11 @@ class NativeCxxModuleExampleExample extends React.Component<{||}, State> {
           console.log(`onSubmit: (${JSON.stringify(value)})`),
         ),
       );
+      this.eventSubscriptions.push(
+        NativeCxxModuleExample.onEvent(value =>
+          console.log(`onEvent: (${value.valueOf()})`),
+        ),
+      );
     }
   }