One problem is that we need to use androidTestImplemention instead of testImplementation when declaring the dependency for UI tests. I think we also need to move the WebserverRule to support-android-test (instead of support-test), because we'll get into classpath issues with Robolectric otherwise. You can confirm by running the SmokeTests locally.
We should have caught this in the PR build, but the UI tests don't seem to run for those builds. We'll look into that too.