message: Alias preferred_dtype argument with dtype_hint
  In order to easily transition internal uses of ops.convert_to_tensor to
  use ops.internal_convert_to_tensor, we add the dtype_hint argument to
  match the signature of ops.convert_to_tensor.
diff: @@ -1261,9 +1261,12 @@ def internal_convert_to_tensor(value,
  name=None,
  as_ref=False,
  preferred_dtype=None,
  + dtype_hint=None,
  ctx=None,
  accepted_result_types=(Tensor,)):
  """Implementation of the public convert_to_tensor."""
  + # TODO(b/142518781): Fix all call-sites and remove redundant arg
  + preferred_dtype = preferred_dtype or dtype_hint
  if isinstance(value, EagerTensor):
  if ctx is None:
  ctx = context.context()
  