Unrename cpp tests

tools/internal_ci/linux/grpc_xds_cpp.cfg → tools/internal_ci/linux/grpc_xds.cfg

@@ -19,5 +19,5 @@ build_file: "grpc/tools/internal_ci/linux/grpc_bazel.sh"
 timeout_mins: 90
 env_vars {
   key: "BAZEL_SCRIPT"
-  value: "tools/internal_ci/linux/grpc_xds_cpp_bazel_test_in_docker.sh"
+  value: "tools/internal_ci/linux/grpc_xds_bazel_test_in_docker.sh"
 }