OnRep functions not overrideable in child BPs

The function that is Auto-Generated when creating RepNotify Variables is not overrideable in child blueprints.

(Potentially involved with the inability to add inputs/outputs to OnRep_ functions)

1. Create an Actor BP
2. Add Variable, Set Variable Replication to RepNotify
3. Create a child of this BP
4. Observe that the auto-generated OnRep_Variable function (Visible in ParentBP) is not overridable

Expected: OnRep fuctions overrideable in child BPs