docs(examples): Update useAppState in react-native example (#5557)

* Update useAppState.ts

Updating the cleanup function as the removeEventLister method is not available on AppState

* Update useAppState.ts

Removed Semicolons

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Co-authored-by: Dominik Dorfmeister <office@dorfmeister.cc>

Author: ursrudra

examples/react/react-native/src/hooks/useAppState.ts

@@ -3,9 +3,9 @@ import { AppState, AppStateStatus } from 'react-native'
 
 export function useAppState(onChange: (status: AppStateStatus) => void) {
   useEffect(() => {
-    AppState.addEventListener('change', onChange)
+    const subscription = AppState.addEventListener('change', onChange)
     return () => {
-      AppState.removeEventListener('change', onChange)
+      subscription.remove()
     }
   }, [onChange])
 }