Blackboard keys in hierarchies do not get updated on editor changes to parent BB asset

Editor-time changes to parent BB asset do not get propagated to derived BB assets.

1. Open the editor and open a BlackboardData asset that serves as the parent for another asset.
2. Add a new key to the Parent BlackboardData asset.
3. Start PIE and spawn an AI that uses the derived BlackboardData asset.
4. Break in UBlackboardComponent::InitializeBlackboard and notice that the FirstKeyID is off by one.