fix: participant management insert date (#1691)

Author: will-larkin-nhs

application/CohortManager/src/Functions/Shared/Model/Participant.cs

@@ -198,8 +198,8 @@ public ParticipantManagement ToParticipantManagement(ParticipantManagement exist
             ExceptionFlag = MappingUtilities.ParseStringFlag(ExceptionFlag ?? "0"),
             BlockedFlag = MappingUtilities.ParseStringFlag(BlockedFlag ?? "0"),
             ReferralFlag = existingRecord.ReferralFlag,
-            RecordInsertDateTime = MappingUtilities.ParseDates(RecordInsertDateTime),
-            RecordUpdateDateTime = existingRecord.RecordInsertDateTime,
+            RecordInsertDateTime = existingRecord.RecordInsertDateTime,
+            RecordUpdateDateTime = existingRecord.RecordUpdateDateTime,
             IsHigherRisk = existingRecord.IsHigherRisk
         };