MB: Add low_bandwidth_audio_test to isolate map.

tools-webrtc/mb/gn_isolate_map.pyl

 # Copyright (c) 2016 The WebRTC 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 in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 # gn_isolate_map.pyl - A mapping of Ninja build target names to GN labels and
 # test type classifications for the tests that are run on the bots.
@@ skipping 29 matching lines @@
     "type": "console_test_launcher",
   },
   "common_video_unittests": {
     "label": "//webrtc/common_video:common_video_unittests",
     "type": "console_test_launcher",
   },
   "libjingle_peerconnection_android_unittest": {
     "label": "//webrtc/sdk/android:libjingle_peerconnection_android_unittest",
     "type": "additional_compile_target",
   },
+  "low_bandwidth_audio_test": {
+    "label": "//webrtc/audio:low_bandwidth_audio_test",
+    "type": "console_test_launcher",
+  },
   "modules_tests": {
     "label": "//webrtc/modules:modules_tests",
     "type": "console_test_launcher",
   },
   "modules_unittests": {
     "label": "//webrtc/modules:modules_unittests",
     "type": "windowed_test_launcher",
   },
   "ortc_unittests": {
     "label": "//webrtc/ortc:ortc_unittests",
@@ skipping 41 matching lines @@
   },
   "webrtc_nonparallel_tests": {
     "label": "//webrtc:webrtc_nonparallel_tests",
     "type": "non_parallel_console_test_launcher",
   },
   "webrtc_perf_tests": {
     "label": "//webrtc:webrtc_perf_tests",
     "type": "console_test_launcher",
   },
 }