message: Fix documentation string for conv2d padding argument.
diff: @@ -1818,7 +1818,7 @@ def conv2d_v2(input, # pylint: disable=redefined-builtin
  value is given it is replicated in the `H` and `W` dimension. By default
  the `N` and `C` dimensions are set to 1. The dimension order is determined
  by the value of `data_format`, see below for details.
  - padding: Either the `string `"SAME"` or `"VALID"` indicating the type of
  + padding: Either the `string` `"SAME"` or `"VALID"` indicating the type of
  padding algorithm to use, or a list indicating the explicit paddings at
  the start and end of each dimension. When explicit padding is used and
  data_format is `"NHWC"`, this should be in the form `[[0, 0], [pad_top,
  