Use remove_build_metadata.py on all the trybots (take 3).

scripts/slave/recipes/chromium_trybot.expected/swarming_missing_isolated.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]/scripts/slave/bot_update.py",
       "--master",
       "tryserver.chromium.linux",
       "--builder",
       "linux_chromium_rel",
@@ skipping 203 matching lines @@
       "base_unittests_run",
       "browser_tests",
       "browser_tests_run"
     ],
     "name": "compile (with patch)"
   },
   {
     "cmd": [
       "python",
       "-u",
+      "[BUILD]/scripts/slave/recipe_modules/isolate/resources/remove_build_metadata.py",
+      "--build-dir",
+      "[SLAVE_BUILD]/src/out/Release",
+      "--src-dir",
+      "[SLAVE_BUILD]/src"
+    ],
+    "cwd": "[SLAVE_BUILD]",
+    "name": "remove_build_metadata"
+  },
+  {
+    "cmd": [
+      "python",
+      "-u",
       "\nimport glob\nimport sys\nwith open(sys.argv[1], 'w') as f:\n  f.write('\\n'.join(glob.glob(sys.argv[2])))\n",
       "/path/to/tmp/",
       "[SLAVE_BUILD]/src/out/Release/*.isolated.gen.json"
     ],
     "name": "find isolated targets"
   },
   {
     "cmd": [
       "python",
       "-u",
@@ skipping 293 matching lines @@
       "@@@STEP_TEXT@TEST RESULTS WERE INVALID@@@",
       "@@@STEP_FAILURE@@@"
     ]
   },
   {
     "name": "$final_result",
     "reason": "Step('browser_tests') failed with return_code 1",
     "status_code": 1
   }
 ]