Fix iteration over argument mapping on web (#1504)
Fix iteration over argument mapping on web (#1504)

`index of` was reading properties and indexes instead of reading only indexes which made the next line `const [key, value] = argMapping[index]` crash
kmagiera/react-native-gesture-handler,kmagiera/react-native-gesture-handler,kmagiera/react-native-gesture-handler,kmagiera/react-native-gesture-handler,kmagiera/react-native-gesture-handler