fix API: normalize_program (#33384)

* fix: paddle.static.default_main_program. test=develop

* add normalize_program to __all__. test=develop

python/paddle/static/__init__.py

@@ -85,6 +85,7 @@ __all__ = [     #noqa
            'load',
            'save_inference_model',
            'load_inference_model',
+           'normalize_program',
            'load_program_state',
            'set_program_state',
            'cpu_places',

python/paddle/static/io.py

@@ -157,7 +157,7 @@ def normalize_program(program, feed_vars, fetch_vars):
             exe.run(paddle.static.default_startup_program())
 
             # normalize main program.
-            program = default_main_program()
+            program = paddle.static.default_main_program()
             normalized_program = paddle.static.normalize_program(program, [image], [predict])
 
     """