message: Fix initializers
  Summary:
  Fix initalizers
  Ref T21370
  Test Plan: All tests pass in v2
  Reviewers: #tensorflow, #framework_ip_review_-_any_oss_or_third-party_code_use_has_been_approved, jakeh
  Maniphest Tasks: T21370
diff: @@ -147,6 +147,10 @@ class _PopnnRNN(Layer):
  if self._bias_initializer is None:
  self._bias_initializer = init_ops.zeros_initializer()
  + self._kernel_initializer = initializers.get(self._kernel_initializer)
  + self._recurrent_initializer = initializers.get(self._recurrent_initializer)
  + self._bias_initializer = initializers.get(self._bias_initializer)
  +
  # Initialize the input weight tensor.
  kernel_shape = self.canonical_weight_shape
  kernel_shape[0] -= self.num_units
  