I noticed when fixing MGOMIRROR-587 that the server, when it receives an `applyOps` for time-series collection creation, auto-creates the time/meta index.

This happens despite that the index itself is a separate oplog entry.

This issue is fairly easy to accommodate by just dropping the index after collection creation, but it’s still unexpected behavior in the server. joan.bruguera-mico@mongodb.com suggested that I open this ticket.