fix decay param in DecayAdagrad test=develop (#22026)

python/paddle/fluid/optimizer.py

@@ -2098,7 +2098,8 @@ class DecayedAdagradOptimizer(Optimizer):
             },
             outputs={"ParamOut": param_and_grad[0],
                      "MomentOut": moment_acc},
-            attrs={"epsilon": self._epsilon},
+            attrs={"epsilon": self._epsilon,
+                   "decay": self._decay},
             stop_gradient=True)
 
         return decayed_adagrad_op