fix compatibility with rn > 0.50 method does not override or implement a method from a supertype

[alzalabany]

react native breaking change now this lib will fail to build with error

/node_modules/react-native-filesystem/android/src/main/java/com/benwixen/rnfilesystem/RNFileSystemPackage.java:18: error: method does not override or implement a method from a supertype
  @Override
  ^

[aike19115]

The plugin is not compatible with React Native versions >= 0.47 because of a breaking change in React Native. Take this pull request to use the plugin: https://github.com/benwixen/react-native-filesystem/pull/13/files

[mividtim]

@benwixen I see that this PR was accepted in March. Could you please publish the update to NPM? Thanks!