message: [LINKEDIN-AVRO] Fix trunk blocker -- shape error
  Why? Trunk blocker
  What? Need to add None in python (which will be represented as -1 in c++) dimension to fixed len features during parsing for batch
  RB=2003824
  G=tensorflow-reviewers,tony-reviewers
  A=ashahab
diff: @@ -130,6 +130,25 @@ def _parse_avro(serialized,
  return dict(zip(sparse_keys + dense_keys, sparse_tensors + dense_values))
  +# Adjusted from
  +# https://github.com/tensorflow/tensorflow/blob/v2.0.0/tensorflow/python/ops/parsing_ops.py
  +# _prepend_none_dimension with the following changes
  +# - Removed the warning
  +# - Switched this to FixedLenFeature -- instead of FixedLenSequenceFeature
  +def _prepend_none_dimension(features):
  + if features:
  + modified_features = dict(features) # Create a copy to modify
  + for key, feature in features.items():
  + if isinstance(feature, parsing_ops.FixedLenFeature):
  + modified_features[key] = parsing_ops.FixedLenFeature(
  + [None] + list(feature.shape),
  + feature.dtype,
  + feature.default_value)
  + return modified_features
  + else:
  + return features
  +
  +
  def _build_keys_for_sparse_features(features):
  """
  Builds the fully qualified names for keys of sparse features.
  