Base setting with a stochastic next-frame model.

def rlmb_base_stochastic():
  """Base setting with a stochastic next-frame model."""
  hparams = rlmb_base()
  hparams.initial_epoch_train_steps_multiplier = 5
  hparams.generative_model = "next_frame_basic_stochastic"
  hparams.generative_model_params = "next_frame_basic_stochastic"
  return hparams