app/src/release/res/values/google_maps_api.xml
<resources>
<!--
TODO: Before you release your application, you need a Google Maps API key.
To do this, you can either add your release key credentials to your existing
key, or create a new key.
Note that this file specifies the API key for the release build target.
If you have previously set up a key for the debug target with the debug signing certificate,
you will also need to set up a key for your release certificate.
Follow the directions here:
https://developers.google.com/maps/documentation/android/signup
Once you have your key (it starts with "AIza"), replace the "google_maps_key"
string in this file.
-->
<string name="google_maps_key" templateMergeStrategy="preserve" translatable="false">YOUR_KEY_HERE</string>
</resources>