Remove experimental modules from top level API

PiperOrigin-RevId: 399870959

Author: daverim

tensorflow_model_optimization/python/core/api/quantization/keras/__init__.py

@@ -20,7 +20,6 @@
 from tensorflow_model_optimization.python.core.api.quantization.keras import default_8bit
 from tensorflow_model_optimization.python.core.api.quantization.keras import graph_transformations
 from tensorflow_model_optimization.python.core.api.quantization.keras import collaborative_optimizations
-from tensorflow_model_optimization.python.core.api.quantization.keras import experimental
 
 # quantize all layers with default quantization implementation.
 from tensorflow_model_optimization.python.core.quantization.keras.quantize import quantize_model

tensorflow_model_optimization/python/core/quantization/keras/quantize.py

@@ -25,7 +25,6 @@
 from tensorflow_model_optimization.python.core.quantization.keras import quantizers
 from tensorflow_model_optimization.python.core.quantization.keras.default_8bit import default_8bit_quantize_registry
 from tensorflow_model_optimization.python.core.quantization.keras.default_8bit import default_8bit_quantize_scheme
-from tensorflow_model_optimization.python.core.quantization.keras.experimental.default_n_bit import default_n_bit_quantize_registry
 
 keras = tf.keras
 
@@ -71,8 +70,6 @@ def quantize_scope(*args):
       'QuantizeLayer': quantize_layer.QuantizeLayer,
       'OutputOnlyConfig': quantize_config_mod.OutputOnlyConfig,
   }
-  quantization_objects.update(default_8bit_quantize_registry._types_dict())  # pylint: disable=protected-access
-  quantization_objects.update(default_n_bit_quantize_registry._types_dict())  # pylint: disable=protected-access
   quantization_objects.update(quantizers._types_dict())  # pylint: disable=protected-access
 
   return tf.keras.utils.custom_object_scope(*(args + (quantization_objects,)))