[infra/config] Actually set properties_j in the right place.

infra/config/PRESUBMIT.py

+# Copyright 2019 The ANGLE Project Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+
+def CheckChangeOnUpload(input_api, output_api):
+    return input_api.canned_checks.CheckChangedLUCIConfigs(input_api, output_api)
+
+
+def CheckChangeOnCommit(input_api, output_api):
+    return input_api.canned_checks.CheckChangedLUCIConfigs(input_api, output_api)

infra/config/global/cr-buildbucket.cfg

@@ -60,11 +60,13 @@ builder_mixins {
 builder_mixins {
   name: "mac"
   dimensions: "os:Mac"
+  recipe {
     properties_j: <<EOF
       $depot_tools/osx_sdk:{
         "sdk_version": "10b61"
       }
     EOF
+  }
 }
 
 builder_mixins {