Long setting with stochastic discrete model & deterministic sim starts.

def rlmb_long_stochastic_discrete_simulation_deterministic_starts():
  """Long setting with stochastic discrete model & deterministic sim starts."""
  hparams = rlmb_base_stochastic_discrete()
  hparams.generative_model_params = "next_frame_basic_stochastic_discrete_long"
  hparams.ppo_epochs_num = 1000
  hparams.simulation_random_starts = False
  return hparams