refine_collection_shard_key_basic.js checks if entries associated with refineCollectionShardKey are correctly inserted into the changelog.
In the case that the primary stepdown do to a failure, it is not guaranteed that these entries are committed on the changelog.
In particular for every refineCollectionShardKey operation it could be possible to have:
- one or more `refineCollectionShardKey.start` entry in the changelog
- one or zero `refineCollectionShardKey.end` entry in the changelog.
Unfortunately the two implemented solution failed to address the problem.
The bug was introduced by: