This test currently simulates failure by pre-deleting the store
directory for 'file3' which is the second of a two-store import
operation. The goal is to assert that the later failure reverts
the import of the earlier 'file2' store. However, the way the
polling loop works is that we break out once 'file2' has completed,
and then assume that 'file3' has already failed and reverted.
This is a race, and one we're losing consistently in CI.
This patch waits for the failure of 'file3' to be reported, as
well as the revert of 'file2' to occur before exiting the polling
loop and checking the final state of things to ensure that the
revert has actually happened. This addresses the non-determinism
inherent in the original test.
(cherry picked from commit