fix uniform random (#21009)

* fix uniform random; test=develop

* add uniform random test; test=develop

python/paddle/fluid/layers/nn.py

@@ -17854,7 +17854,7 @@ def uniform_random(shape, dtype='float32', min=-1.0, max=1.0, seed=0):
     inputs = dict()
     attrs = {'seed': seed, 'min': min, 'max': max}
     if in_dygraph_mode():
-        attrs = {'shape': shape}
+        attrs['shape'] = shape
     else:
         if isinstance(shape, Variable):
             shape.stop_gradient = True

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

@@ -416,5 +416,15 @@ class TestUniformRandomOpSelectedRowsShapeTensorList(unittest.TestCase):
                 hist, prob, rtol=0, atol=0.01), "hist: " + str(hist))
 
 
+class TestUniformRandomDygraphMode(unittest.TestCase):
+    def test_check_output(self):
+        with fluid.dygraph.guard():
+            x = fluid.layers.uniform_random(
+                [10], dtype="float32", min=0.0, max=1.0)
+            x_np = x.numpy()
+            for i in range(10):
+                self.assertTrue((x_np[i] > 0 and x_np[i] < 1.0))
+
+
 if __name__ == "__main__":
     unittest.main()