docs: Update AutoML Video docstring (#987)

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Fixes #<issue_number_goes_here> 🦕

google/cloud/aiplatform/training_jobs.py

@@ -5919,7 +5919,7 @@ def run(
         model_labels: Optional[Dict[str, str]] = None,
         sync: bool = True,
     ) -> models.Model:
-        """Runs the AutoML Image training job and returns a model.
+        """Runs the AutoML Video training job and returns a model.
 
         If training on a Vertex AI dataset, you can use one of the following split configurations:
             Data fraction splits: