Given a replica set with primary node 7.3 and secondary nodes 8.0 (FCV 7.3), the CollModTimeseriesBucketsMayHaveMixedSchemaData feature flag would be enabled (by default) on the primary but not on the secondaries. When secondaries parse a collMod request, they could experience the timeseriesBucketsMayHaveMixedSchemaData parameter set with the feature flag disabled. This triggers the InvalidOptions error causing the process to terminate (fatal assert).

This check should be executed by the primary node only.