Make sample redux example work with latest dependencies versions

### Version
Tell us which versions you are using:
- react-native-router-flux v4.0.6
- react v16.8.6
- react-native v0.59.4

### Expected behaviour

I expect [the sample project](https://github.com/aksonov/react-native-router-flux/tree/master/examples/redux/android) to work with latest versions of react-native

### Actual behaviour

I got [this error](https://stackoverflow.com/questions/55299138/could-not-get-unknown-property-mergeresourcesprovider-for-object-of-type-com) and was requested to upgrade gradle version.

After upgrading gradle, I'm able to build the project, but I get on my phone:

`Unable to load script. Make sure you're either running a metro server...`

Of course, I have the server running with no error: `Running Metro Bundler on port 8081`.

If I try to reload, I get a new error:

`Could not connect to development server`

I already tried to go to `Dev settings -> Debug server host & port for device` and set the `192.168.:8081`

### Steps to reproduce
For non-obvious bugs, please fork this component, modify Example project to reproduce your issue and include link here.
1. git clone https://github.com/Sharcoux/redux.git
2. cd redux
3. yarn install
4. react-native run-android

### Reproducible Demo

Cf above