Add support for protobuf versions before 3.20

Copied the previous version of the generated file.
Use the previous version if the protobuf version is before 3.20

PiperOrigin-RevId: 517006172

Author: MarkDaoust

site/en/tutorials/audio/music_generation.ipynb

@@ -1081,7 +1081,7 @@
         "  # Add batch dimension\n",
         "  inputs = tf.expand_dims(notes, 0)\n",
         "\n",
-        "  predictions = keras_model.predict(inputs)\n",
+        "  predictions = model.predict(inputs)\n",
         "  pitch_logits = predictions['pitch']\n",
         "  step = predictions['step']\n",
         "  duration = predictions['duration']\n",

tools/tensorflow_docs/api_generator/report/schema/__init__.py

@@ -14,4 +14,18 @@
 # ==============================================================================
 """Public API for api report proto."""
 
-from tensorflow_docs.api_generator.report.schema import api_report_generated_pb2 as api_report_pb2
+import sys
+
+from google import protobuf
+
+_version_parts = protobuf.__version__.split('.')
+_version = (int(_version_parts[0]), int(_version_parts[1]))
+
+if _version >= (3, 20):
+  from tensorflow_docs.api_generator.report.schema import api_report_generated_pb2 as api_report_pb2  # pylint: disable=g-import-not-at-top
+else:
+  from tensorflow_docs.api_generator.report.schema import api_report_generated_319_pb2 as api_report_pb2  # pylint: disable=g-import-not-at-top
+
+sys.modules['tensorflow_docs.api_generator.report.schema.api_report_pb2'] = (
+    api_report_pb2
+)