Use staging Firebase project for QA builds (QA for Analytics)

[theodur]

Description

The recommended approach for testing analytics for a staging environment in Firebase is to create a new Firebase project for that environment. Based off the work in https://github.com/department-of-veterans-affairs/va-mobile-app/issues/7226, a staging environment in Firebase called va-mobile-app-staging was created. Logging anaytics to this environment was tested locally by replacing the GoogleService-Info.plist and google-services.json files with the files specific to the staging environment. In order for this environment to be used in QA builds, we need to update the build process to determine when to use the staging project's GoogleService-Info.plist and google-services.json files vs the production version.

Note: One issue with using the staging environment for testing was the delay in the events being logged. Even when using the Realtime Analytics Dashboard, there was a significant delay (over an hour) in when the analytics would be logged. This isn't an issue specific to the staging Firebase project, but just a Firebase issue in general.

Acceptance Criteria

• [ ] Add the staging project's GoogleService-Info.plist and google-services.json files to GHA secrets so they can be referenced during the build process
• [ ] Update the build process to use the staging project's GoogleService-Info.plist and google-services.json files for on demand and RC builds

Related issues

https://github.com/department-of-veterans-affairs/va-mobile-app/issues/7226

[bischoffa]

Removed QA and Release team tag as its tagged with Global and being worked by global team.