Rework the Gradle modules for more flexibility

[TimoPtr]

Today we have already multiple Gradle modules

• :build-logic:convention
• :app
• :automotive
• :common
• :lint
• :testing-unit
• :wear

This is allowing us a separation of concern at a high level. The current split is not very flexible every application module depends on :common, but we might want to share things between 2 app modules and not with :wearfor instance.
Instead we could make the app modules smaller and put the features into dedicated module like :onboarding, :settings, :webview. This would allow us to compose an application module with the features we want using the compose navigation framework and hilt.

We could push the idea further and split :common into smaller pieces more specific to reduce the scope of each module, and avoid having compose code and network code in the same module.

Don't hesitate to share your pros/cons.

[dshokouhi]

I think this would be a great idea, I can see the need for a :google module so we can move things liek location tracking to a shared module and do things like give Wear OS a device tracker without duplicating code :)

[jpelgrom]

While I generally like this idea, we should be mindful of unnecessary complexity where we don't need a split right now, and making it accessible to new contributors. The current structure is easy enough to follow; if you have to edit 6 modules to add one feature that might be a bit daunting.

[TimoPtr]

Good point, when creating module we should aim at keeping the entry level easy 👍🏻. At the same time having multiple module could help a new contributor to stay focus on his feature and not be polluted by other module while using auto-completion.