Per T328969: AQS 2.0: Revisit in-service testing approach, we are refactoring in-service tests to separate "unit" tests, which have no external dependencies, from "integration" tests, which may depend on a datastore external to the service

We are making these changes first in Device Analytics. But once they are complete and our approach is solid, the changes should be synchronized to the other services. This task is a placeholder to remind us to do that work. We may find it useful to create a subtask for each of the other services once we start this work.