test(__tests__/getters): adding tests for getAvailableLocationProviders*
test(__tests__/getters): adding tests for getAvailableLocationProviders*

adds tests for the functions, `getAvailableLocationProviders*` with tests for all supported
platforms

re #1108

rebeccahughes/react-native-device-info,rebeccahughes/react-native-device-info,rebeccahughes/react-native-device-info,rebeccahughes/react-native-device-info,rebeccahughes/react-native-device-info,rebeccahughes/react-native-device-info