FEAT: [CORE REGISTRY API] - Port changes made in CADT (related to null update on CreatedAt as well as no kv diff generations) to core registry CADT

[ccornick]

Need to apply the changes that were made in CADT update for version 1.7.15 (no kv diff generations and ignoring nulls for UpdatedAt and CreatedAt entries) to Core Registry CADT.