Use GroupNormalization layer from tf.leras.layers instead of from TF addons.

PiperOrigin-RevId: 524130269

official/modeling/activations/mish.py

@@ -16,11 +16,9 @@
 
 import tensorflow as tf
 
-from tensorflow_addons.utils import types
-
 
 @tf.keras.utils.register_keras_serializable(package='Text')
-def mish(x: types.TensorLike) -> tf.Tensor:
+def mish(x) -> tf.Tensor:
   """Mish activation function.
 
      Mish: A Self Regularized Non-Monotonic Activation Function

official/vision/modeling/layers/nn_layers.py

@@ -18,7 +18,6 @@ from typing import Any, Callable, Dict, List, Mapping, Optional, Tuple, Union
 
 from absl import logging
 import tensorflow as tf
-import tensorflow_addons as tfa
 
 from official.modeling import tf_utils
 from official.vision.ops import spatial_transform_ops
@@ -351,7 +350,7 @@ class PanopticFPNFusion(tf.keras.Model):
         'kernel_regularizer': kernel_regularizer,
         'bias_regularizer': bias_regularizer,
     }
-    norm = tfa.layers.GroupNormalization
+    norm = tf.keras.layers.GroupNormalization
     conv2d = tf.keras.layers.Conv2D
     activation_fn = tf_utils.get_activation(activation)
     if tf.keras.backend.image_data_format() == 'channels_last':