Aggregation.ApplySupportedDefaults: use PATCH logic when overriding with ApplySupported

ApplySupportedDefaults allows to specify aggregation defaults on the entity container, applying to all entity sets. This default behavior can be overridden on entity-set level via ApplySupported whose type inherits from the type of ApplySupportedDefaults.

Clarify that this "override" uses PATCH semantics, i.e. values not specified via ApplySupported are "inherited" from ApplySupportedDefaults.