void SetActivityAvailability ( const [FUniqueNetId](API\Runtime\CoreOnline\Online\FUniqueNetId) & LocalUserId, const [FString](API\Runtime\Core\Containers\FString) & ActivityId, const bool bEnabled, [FOnSetActivityAvailabilityComplete](API\Plugins\OnlineSubsystem\Interfaces\FOnSetActivityAvailabilityComple-) CompletionDelegate )