Saving Data on Android

Configuring applica/on
You have created the database in the console. Now you need to configure your app so 
it can communicate with the database.
NOTE:
 This chapter provides 
starter
 and 
final
 projects that you can use to 
follow along. In order to use those projects, you need to configure them first 
by creating a project in the Firebase and by adding 
google-services.json
 
configuration file to the project. Take a look at "Chapter 11: Firebase overview" 
and "Chapter 12: Introduction to Firebase Realtime database" to see how to do 
that.
Open the 
starter
 project for this chapter.
First, you need to add a Firestore client library for Android to the project. Open the 
apps level