How to check if a Firebase App is already initialized on Android

In v9, Firebase has been modularized for better tree shaking. So we can no longer import entire app and check the apps property AFAIK. The below approach can be used instead.

import { initializeApp, getApps, getApp } from "firebase/app";
getApps().length === 0 ? initializeApp(firebaseConfig) : getApp();

https://firebase.google.com/docs/reference/js/v9/app.md#getapps for documentation

On firebase web, you check if already initialized with:

if (firebase.apps.length === 0) {
    firebase.initializeApp({});
}