Add the firebase-java-sdk

[nbransby]

Link to project (GitHub): https://github.com/GitLiveApp/firebase-java-sdk

Describe the project in 2-3 sentences: The Firebase Java SDK is a pure java port of the Firebase Android SDK

Why would Firebase developers be interested in this project?: To use Firebase in pure java clientside environments such as Compose Multiplatform desktop.

Have you added a .opensource/project.json file to your site: Yes

Examples:

• https://github.com/invertase/react-native-firebase/blob/master/.opensource/project.json
• https://github.com/sgarciac/fuego/blob/master/.opensource/project.json
• https://github.com/firebase/emberfire/blob/master/.opensource/project.json