working android example?

I have done all the things which are descriped in the readme.

when i want to run the app it says i have to change the distributionUrl in
/gradle/wrapper/gradle-wrapper.properties
to
https\://services.gradle.org/distributions/gradle-4.4-all.zip

i did it and gave it another try. Next error was:

```
> Task :app:processDebugGoogleServices
Parsing json file: /home/t/mobileBlitzer/android/app/google-services.json

/home/t/mobileBlitzer/android/app/build/intermediates/manifests/full/debug/AndroidManifest.xml:56: AAPT: error: resource mipmap/ic_notif (aka com.mobileblitzer:mipmap/ic_notif) not found.

error: failed processing manifest.

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:processDebugResources'.
> Failed to process resources, see aapt output above for details.

```

Has somebody a working exmaple? The exmple Project in this repo does not work for me. I only want to send a little message from my backend to my users. No speciall things...

here is my package.json

```
{
"name": "mobileBlitzer",
"version": "0.0.1",
"private": true,
"scripts": {
"start": "node node_modules/react-native/local-cli/cli.js start",
"test": "jest"
},
"dependencies": {
"react": "16.3.1",
"react-native": "0.55.3",
"react-native-fcm": "^16.0.0"
},
"devDependencies": {
"babel-jest": "23.4.0",
"babel-preset-react-native": "4.0.0",
"jest": "23.4.1",
"react-test-renderer": "16.3.1"
},
"jest": {
"preset": "react-native"
}
}

```