add data type for onClose/onCancel
add data type for onClose/onCancel

testshallpass/react-native-dropdownalert,devBrian/react-native-dropdownalert,devBrian/react-native-dropdownalert,testshallpass/react-native-dropdownalert,testshallpass/react-native-dropdownalert,devBrian/react-native-dropdownalert