chore: Add protobuf-java-util testing scope

Author: lqiu96

google-cloud-bigquerystorage/pom.xml

@@ -232,6 +232,11 @@
       <artifactId>arrow-memory-core</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>com.google.protobuf</groupId>
+      <artifactId>protobuf-java-util</artifactId>
+      <scope>test</scope>
+    </dependency>
 
     <dependency>
       <groupId>io.grpc</groupId>