update for AAC Lifecycle 2.5.0

[kenyee]

The AndroidX ViewModel library offers a viewModelScope extension function to provide an auto-cancelled CoroutineScope, but again, this CoroutineScope is hard-coded and uses Dispatchers.Main. This limitation needn't exist.

This is no longer true w/ Lifecycle 2.5.0+:
https://developer.android.com/jetpack/androidx/releases/lifecycle#2.5.0

"addCloseable() API and a new constructor overload that allow you to add one or more Closeable objects to the ViewModel that will be closed when the ViewModel is cleared without requiring any manual work in onCleared()."
So you can pass in a Closable coroutinescope to a viewmodel's constructor.