Basic 2-frame conv model with pixel noise.

def next_frame_pixel_noise():
  """Basic 2-frame conv model with pixel noise."""
  hparams = next_frame_basic_deterministic()
  hparams.add_hparam("video_modality_input_noise", 0.05)
  hparams.bottom["inputs"] = modalities.video_pixel_noise_bottom
  hparams.top["inputs"] = modalities.video_top
  return hparams