UserLifecycleTests: wait for idle before resume timing

Currently, we wait-for-broadcast-idle at the start of each test run.
However, we also have numerous pauses/resumes during individual tests.
We should also do wait-for-broadcast-idle before resuming in those cases.

Test: UserLifecycleTests
Bug: 169449457
Change-Id: I46f49f556b4c5b508c1d9f767871b0377e29a6ae