feat: update spec for ListVariables

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

Author: zong-zhe

java/pom.xml

@@ -44,7 +44,7 @@
         <dependency>
             <groupId>com.google.protobuf</groupId>
             <artifactId>protobuf-java</artifactId>
-            <version>4.27.0</version>
+            <version>3.25.3</version>
         </dependency>
         <dependency>
             <groupId>org.slf4j</groupId>