message: Pass session config properly when using distribution strategy.
diff: @@ -5310,11 +5310,16 @@ def in_multi_worker_mode():
  def configure_and_create_distributed_session(distribution_strategy):
  """Configure session config and create a session with it."""
  - # TODO(priyag): Throw error if a session already exists.
  def _create_session(distribution_strategy):
  """Create the Distributed Strategy session."""
  session_config = get_default_session_config()
  + # If a session already exists, merge in its config; in the case there is a
  + # conflict, take values of the existing config.
  + global _SESSION
  + if getattr(_SESSION, 'session', None) and _SESSION.session._config:
  + session_config.MergeFrom(_SESSION.session._config)
  +
  if is_tpu_strategy(distribution_strategy):
  # TODO(priyag, yuefengz): Remove this workaround when Distribute
  # Coordinator is integrated with keras and we can create a session from
  