Fix trailing comma -> period

The comma was being interpreted incorrectly by the doc generator as part of the URL. Hopefully this will fix that.

PiperOrigin-RevId: 455938190

official/vision/ops/augment.py

@@ -1915,7 +1915,7 @@ def _maybe_identity(x: Optional[tf.Tensor]) -> Optional[tf.Tensor]:
 class RandAugment(ImageAugment):
   """Applies the RandAugment policy to images.
 
-  RandAugment is from the paper https://arxiv.org/abs/1909.13719,
+  RandAugment is from the paper https://arxiv.org/abs/1909.13719.
   """
 
   def __init__(self,