message: Use tensor for output_shape of SparseTensor, based on review feedback
diff: @@ -323,11 +323,11 @@ def sparse_concat(axis,
  gen_sparse_ops.sparse_concat(inds, vals, shapes, axis, name=name))
  shapes_value = [tensor_util.constant_value(shape) for shape in shapes]
  - if not shapes_value and all(shape is not None for shape in shapes_value):
  + if shapes_value and all(shape is not None for shape in shapes_value):
  dim = sum(shape[axis] for shape in shapes_value)
  output_shape = shapes_value[0]
  output_shape[axis] = dim
  - output_shape = tensor_shape.as_shape(output_shape)
  + output_shape = ops.convert_to_tensor(output_shape)
  return sparse_tensor.SparseTensor(output_ind, output_val, output_shape)
  