Build errors after Installing the Relay Gradle plugin

Expected behavior

Relay Gradle Plugin can be installed to the project and the project can be built with no errors afterwards.

Actual behavior

After installing the Relay Gradle Plugin, building the project fails with 100+ errors, all of them related to BuildConfig and usages of values from it in the app's source code.

Steps to reproduce the behavior

1. Open the project in Android Studio
2. Follow the official guide to Install the Relay Gradle plugin
3. Tap Sync Now in Android Studio's notification bar that appears above the file editor
4. Build/Make the project
5. 💣 Verify the build fails with over 100 errors, all saying: Unresolved reference: BuildConfig

Example

Checkout the branch tech/relay-plugin to quickly see the issues.

Note
The tip of the branch is not trunk, but a rebase of trunk + deps/main-batch-androidx-compose-kotlin.
Due to this approach we should be able to check quickly if the pending Compose and related dependencies update doesn't improve something about this issue.

Check out the tech/relay-plugin branch, then follow the documented Relay Gradle plugin installation steps and run a Gradle sync and project build. Investigate the resulting BuildConfig unresolved-reference errors; the work is done when the plugin is installed and the project builds without those errors.