[Epic] Ensure readiness for production release

[luongvo]

Why

The template aims to reduce the developer's effort to build, develop and release Flutter apps to production. So, we should ensure the template is ready for production release on Android and iOS platforms.

This includes various steps & processes:

• Necessary configurations for build flavors, especially the release build.
• Environment variables & secrets management in the app.
• Necessary CI/CD workflows to publish apps to store.

Who Benefits?

Developers

Tasks

Preview Give feedback

1. Update to manage secrets with Github Environments for Staging and Production #226
   type : chore +1
   
2. [Android] Add signing config for debug and release builds #229
   type : feature +1
   
3. Add Firebase to the base template as an "optional feature" #225
   type : feature +1
   
4. [Android] Update android_deploy_production.yml to build and distribute release build #268
   type : feature +1
   
5. [iOS] Create a new workflow ios_deploy_production.yml to build and distribute production release build