Android: Support Google Play Games Services for user config backup

Problem

Creating a backup of user data on Android (ex: changing devices) require exporting the worlds and config and importing then on another device, which is acceptable but not really user friendly.

Solutions

Integrate with the Google Play Game Services => allow the creation/loading of game config and favorite servers backups on the user Google Drive.

These are just snapshots of game data (entirely optional), size only limited by available space on the Google Drive.

EDIT: It looks like I was wrong here, it seems limited to 3Mo by snapshot so will not allow to save entire worlds. But is still is a good idea I think for user config / favorite servers, etc

Alternatives

Keep the current solution.

Additional context

https://developers.google.com/games/services/common/concepts/savedgames

https://developers.google.com/games/services/android/savedgames