Dilated hparams.

def imagetransformer_base_8l_8h_big_cond_dr03_dan_dilated():
  """Dilated hparams."""
  hparams = imagetransformer_base_8l_8h_big_cond_dr03_dan()
  hparams.gap_sizes = [0, 16, 64, 0, 16, 64, 128, 0]
  hparams.dec_attention_type = cia.AttentionType.DILATED
  hparams.block_length = 128
  hparams.block_width = 128
  hparams.add_hparam("num_memory_blocks", 1)
  return hparams