fix autoencoder memory tests (#13734)

Author: sayakpaul

tests/models/autoencoders/test_models_autoencoder_kl.py

@@ -47,6 +47,10 @@ class AutoencoderKLTesterConfig(BaseModelTesterConfig):
     def model_class(self):
         return AutoencoderKL
 
+    @property
+    def main_input_name(self) -> str:
+        return "sample"
+
     @property
     def output_shape(self):
         return (3, 32, 32)