If we try to add an invariant on a bucket not being prepared before preparing a bucket's state, it will be tripped by running: 

buildscripts/resmoke.py run --repeat=5 --suites=concurrency_replication jstests/concurrency/fsm_workloads/timeseries_insert_kill_op.js

It's not clear how we can get into this situation so the goal of this ticket will be to look into the conditions required to hit this invariant and figure out if we are missing some logic to add this invariant.