During the restore of a backup in hot backup/restore tests, each node goes through a series of restart cycles, each with different startup options and operations. At some point, both in the PIT and non-PIT paths, the node is started with "takeUnstableCheckpointOnShutdown: true". After this point, turns out that validate() could find inconsistencies in some collections as it was found in BF-40419. Those validation failures appear to be false positives. The goal of this ticket is to omit validation on all restart cycles after and including "takeUnstableCheckpointOnShutdown: true", but not including the final bring up when the node is started as a replica set.