add public_python_api

Author: xiaoguoguo626807

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

@@ -1464,6 +1464,7 @@ class TestCos(TestActivation):
     def setUp(self):
         self.op_type = "cos"
         self.python_api = paddle.cos
+        self.public_python_api = paddle.cos
         self.prim_op_type = "prim"
         self.init_dtype()
         self.init_shape()
@@ -1599,6 +1600,7 @@ class TestSin(TestActivation, TestParameter):
     def setUp(self):
         self.op_type = "sin"
         self.python_api = paddle.sin
+        self.public_python_api = paddle.sin
         self.prim_op_type = "prim"
         self.init_dtype()
         self.init_shape()