Enable appending extra parameters to a deep link query string

Developers frequently use an extra query parameter like `&twa=1` to segment web traffic coming from the Trusted Web Activity implementation. `LauncherActivity` handles deep links correctly, but doesn't allow configuring appending the extra parameter without developers creating their own `LauncherActivity`.

Ideally, we would allow developers to configure extra parameters via the AndroidManifest. This would allow developers to add extra parameters without having to write Java code and allow llama-pack to help developers to configure it.