Fix bugs in Translated Layer when change mode from train/eval to eval/train (#38141)

* fix bugs in Translated layer when change train/eval

* fix python converage

python/paddle/fluid/dygraph/io.py

@@ -1286,9 +1286,11 @@ class TranslatedLayer(layers.Layer):
 
     def train(self):
         self._is_test = False
+        self.training = True
 
     def eval(self):
         self._is_test = True
+        self.training = False
 
     def program(self, method_name='forward'):
         """

python/paddle/fluid/tests/unittests/test_translated_layer.py

@@ -48,6 +48,7 @@ class LinearNet(nn.Layer):
     def __init__(self):
         super(LinearNet, self).__init__()
         self._linear = nn.Linear(IMAGE_SIZE, CLASS_NUM)
+        self._dropout = paddle.nn.Dropout(p=0.5)
 
     @paddle.jit.to_static(input_spec=[
         paddle.static.InputSpec(
@@ -183,6 +184,20 @@ class TestTranslatedLayer(unittest.TestCase):
         for spec_x, spec_y in zip(expect_spec, actual_spec):
             self.assertEqual(spec_x, spec_y)
 
+    def test_layer_state(self):
+        # load
+        translated_layer = paddle.jit.load(self.model_path)
+        translated_layer.eval()
+        self.assertEqual(translated_layer.training, False)
+        for layer in translated_layer.sublayers():
+            print("123")
+            self.assertEqual(layer.training, False)
+
+        translated_layer.train()
+        self.assertEqual(translated_layer.training, True)
+        for layer in translated_layer.sublayers():
+            self.assertEqual(layer.training, True)
+
 
 if __name__ == '__main__':
     unittest.main()