chore(deps): add test scope for grpc-google-common-protos. (#9578)

Author: zhumin8

java-gke-backup/google-cloud-gke-backup/pom.xml

@@ -108,6 +108,7 @@
     <dependency>
       <groupId>com.google.api.grpc</groupId>
       <artifactId>grpc-google-common-protos</artifactId>
+      <scope>test</scope>
     </dependency>
   </dependencies>
 </project>