Intro
Android requires that all apps be digitally signed with a certificate before they can be installed, so to distribute your Android application via Google Play store, you'll need to generate a signed release APK.
Steps on signing android app:
- Generating a signing key
- Setting up gradle variables
- Adding signing config to your app's gradle config
- Generating the release APK
- Testing the release build of your app
Reference: https://facebook.github.io/react-native/docs/signed-apk-android.html