update .d.ts with onTap reference
update .d.ts with onTap reference

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