 Handle return value from permissionsAndroid.request() in react-native[0.56] (#1684)
 Handle return value from permissionsAndroid.request() in react-native[0.56] (#1684)

* Handle return value from permissionsAndroid.request()

According to [documentation](https://facebook.github.io/react-native/docs/permissionsandroid.html): PermissionsAndroid.request() returns a promise resolving to a string value('granted', 'denied' or 'never_ask_again' ), not a boolean value. So there is no need to check  device's API level because if it's below 23, It's always `PermissionsAndroid.RESULTS.GRANTED`.

* 0.56 version compatibility

lwansbrough/react-native-camera,lwansbrough/react-native-camera,lwansbrough/react-native-camera,lwansbrough/react-native-camera