Although we have suites running setFCV upgrade/downgrade in the background (fcv_upgrade_downgrade_*), we don't have any combining setFCV with primary stepdown / kill.

It is hard to tell if any of the tests that run setFCV end up being executed in a stepdown/kill suite, and even if they do, it is probably very improbable that the failover happens when setFCV is executed.

We should add either a suite or a targeted test that exercises this case.