Update generation for symbol removal (#391)

Author: rnett

tensorflow-core/pom.xml

@@ -36,7 +36,11 @@
   </modules>
 
   <properties>
-    <!-- Match version used by TensorFlow, in tensorflow/workspace.bzl -->
+    <!--
+    Match version used by TensorFlow, in
+    https://github.com/tensorflow/tensorflow/blob/master/tensorflow/workspace2.bzl#L567
+    (but for the currently used release, not master)
+    -->
     <protobuf.version>3.9.2</protobuf.version>
 
     <native.classifier>${javacpp.platform}${javacpp.platform.extension}</native.classifier>