[ts] Add constants and export Handler (#327)
[ts] Add constants and export Handler (#327)

Solves #325 
react-native-kit/react-native-track-player,react-native-kit/react-native-track-player,react-native-kit/react-native-track-player,react-native-kit/react-native-track-player,react-native-kit/react-native-track-player