Ok, I've installed work runtime v2.5.0 from the SDK manager. Adding
#AdditionalJar: androidx.work:work-runtime
lets me include the androidx.work packages, and the app compiles without any errors.
However, now the app crashes on startup. If I remove the #AdditionalJar, it doesn't crash, but as soon as I put it back in it does. I don't know if this is something else entirely - maybe I should create a new thread? I've tried looking in the unfiltered logs but it seems like it's crashing before the logger can connect.