Eval set of hparams for model-free PPO.

def rlmf_eval():
  """Eval set of hparams for model-free PPO."""
  hparams = rlmf_original()
  hparams.batch_size = 8
  hparams.eval_sampling_temps = [0.0, 0.5, 1.0]
  hparams.eval_rl_env_max_episode_steps = -1
  hparams.add_hparam("ppo_epoch_length", 128)
  hparams.add_hparam("ppo_optimization_batch_size", 32)
  hparams.add_hparam("ppo_epochs_num", 10000)
  hparams.add_hparam("ppo_eval_every_epochs", 500)
  hparams.add_hparam("attempt", 0)
  hparams.add_hparam("moe_loss_coef", 0)
  return hparams