Fix AttributeError: 'Adam' object has no attribute 'get_updates'

Signed-off-by: Foxglove144 <[email protected]>

Author: Foxglove144

examples/get_started_keras.py

@@ -10,7 +10,7 @@
 from tensorflow.keras.models import Sequential
 from tensorflow.keras.layers import Dense, Flatten, Conv2D, MaxPooling2D
 from tensorflow.keras.losses import categorical_crossentropy
-from tensorflow.keras.optimizers import Adam
+from tensorflow.keras.optimizers.legacy import Adam
 import numpy as np
 
 from art.attacks.evasion import FastGradientMethod