Orleans 7.x does not support multiple stateless worker grain types with different `StatelessWorkerPlacement.MaxLocal` values about orleans

[isaachili]

I have noticed that this happens whenever there are different stateless worker grain types with different stateless worker count limits.

[StatelessWorker(1)]
public class SingleStatelessWorkerGrain : Grain, ISingleStatelessWorkerGrain
{	
}

[StatelessWorker]
public class MultipleStatelessWorkerGrain : Grain, IMultipleStatelessWorkerGrain
{	
}

It seems that the PlacementStrategy used by StatelessWorkerGrainContext is the same instance for both SingleStatelessWorkerGrain and MultipleStatelessWorkerGrain, even though the two grain types have different StatelessWorker attributes, with different MaxLocal values.