Improve naming in idl_msgs_test.cc (#416)

Author: julianadrianheine

ros2_example_bazel_installed/ros2_example_apps/test/idl_msgs_test.cc

@@ -4,9 +4,9 @@
 #include "idl_msgs/srv/query.hpp"
 
 int main() {
-  auto request = std::make_shared<idl_msgs::srv::Query::Request>();
-  request->query = "query";
-  std::cout << "Successfully instantiated Query with query: " << request->query
-            << std::endl;
+  auto query_request = std::make_shared<idl_msgs::srv::Query::Request>();
+  query_request->query = "test";
+  std::cout << "Successfully instantiated Query Request with: "
+            << query_request->query << std::endl;
   return 0;
 }