LineLoginInitializer
Captures the application Context at process start.
This is why LineLogin.configure(LineLoginConfig(...)) needs no Context parameter and can live in shared code. androidx.startup merges the provider into the consumer's manifest, so there is nothing for them to declare.
Apps that strip androidx.startup.InitializationProvider (some do, to shave a few milliseconds off cold start) must call the Android-only LineLogin.configure(context, config) instead. That is the only consequence.
Public because androidx.startup instantiates it reflectively from a manifest string — it is not part of this library's API, and consumer-rules.pro keeps it from being stripped.