move proto files in dependency order

build.json

@@ -405,9 +405,9 @@
       "build": "private",
       "language": "c++",
       "src": [
+        "test/cpp/util/messages.proto",
         "test/cpp/util/echo.proto",
         "test/cpp/util/echo_duplicate.proto",
-        "test/cpp/util/messages.proto",
         "test/cpp/end2end/async_test_server.cc",
         "test/cpp/util/create_test_channel.cc"
       ]