Change the metric string from 'accuracy' to 'acc' to be compatible w/ both TF1.0 & 2.0

PiperOrigin-RevId: 300215182

Author: DualityGap

g3doc/tutorials/adversarial_keras_cnn_mnist.ipynb

@@ -426,7 +426,7 @@
       "outputs": [],
       "source": [
         "base_model.compile(optimizer='adam', loss='sparse_categorical_crossentropy',\n",
-        "                   metrics=['accuracy'])\n",
+        "                   metrics=['acc'])\n",
         "base_model.fit(train_dataset, epochs=HPARAMS.epochs)"
       ]
     },
@@ -566,7 +566,7 @@
       "outputs": [],
       "source": [
         "adv_model.compile(optimizer='adam', loss='sparse_categorical_crossentropy',\n",
-        "                   metrics=['accuracy'])\n",
+        "                   metrics=['acc'])\n",
         "adv_model.fit(train_set_for_adv_model, epochs=HPARAMS.epochs)"
       ]
     },
@@ -632,7 +632,7 @@
         "reference_model.compile(\n",
         "    optimizer='adam',\n",
         "    loss='sparse_categorical_crossentropy',\n",
-        "    metrics=['accuracy'])"
+        "    metrics=['acc'])"
       ]
     },
     {