[RLlib] Fix bug in ModelCatalog when using custom action distribution (#12846)
[RLlib] Fix bug in ModelCatalog when using custom action distribution (#12846)

* return tuple returned from _get_multi_action_distribution when using custom action dict

* Always return dst_class and required_model_output_shape in _get_multi_action_distribution

* pass model config to _get_multi_action_distribution
pcmoritz/ray-1,pcmoritz/ray-1,pcmoritz/ray-1,ray-project/ray,ray-project/ray,pcmoritz/ray-1,ray-project/ray,ray-project/ray,pcmoritz/ray-1,pcmoritz/ray-1,pcmoritz/ray-1,ray-project/ray,ray-project/ray,ray-project/ray,pcmoritz/ray-1,ray-project/ray