Support proper retrying of telemetry_unittests in recipes

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

 [
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]/scripts/slave/bot_update.py",
       "--master",
       "tryserver.chromium",
       "--builder",
       "linux_chromium_rel_swarming",
@@ skipping 352 matching lines @@
       "{\"blamelist\": [\"cool_dev1337@chromium.org\", \"hax@chromium.org\"], \"branch\": \"\", \"build_config\": \"Release\", \"buildername\": \"linux_chromium_rel_swarming\", \"buildnumber\": 571, \"issue\": 12853011, \"mastername\": \"tryserver.chromium\", \"patchset\": 1, \"project\": \"chrome\", \"recipe\": \"chromium_trybot\", \"repository\": \"\", \"requester\": \"commit-bot@chromium.org\", \"revision\": null, \"rietveld\": \"https://codereview.chromium.org\", \"root\": \"src\", \"slavename\": \"TestSlavename\", \"workdir\": \"/path/to/workdir/TestSlavename\"}",
       "--build-properties",
       "{\"blamelist\": [\"cool_dev1337@chromium.org\", \"hax@chromium.org\"], \"branch\": \"\", \"build_config\": \"Release\", \"buildername\": \"linux_chromium_rel_swarming\", \"buildnumber\": 571, \"issue\": 12853011, \"mastername\": \"tryserver.chromium\", \"patchset\": 1, \"project\": \"chrome\", \"recipe\": \"chromium_trybot\", \"repository\": \"\", \"requester\": \"commit-bot@chromium.org\", \"revision\": null, \"rietveld\": \"https://codereview.chromium.org\", \"root\": \"src\", \"slavename\": \"TestSlavename\", \"workdir\": \"/path/to/workdir/TestSlavename\"}",
       "--annotate=gtest",
       "--test-type=telemetry_unittests",
       "--builder-name=linux_chromium_rel_swarming",
       "--slave-name=TestSlavename",
       "--build-number=571",
       "--run-python-script",
       "[SLAVE_BUILD]/src/tools/telemetry/run_tests",
-      "--browser=release"
+      "--browser=release",
+      "--write-full-results-to",
+      "/path/to/tmp/json"
     ],
     "name": "telemetry_unittests (with patch)"
   },
   {
     "allow_subannotations": true,
     "cmd": [
       "python",
       "-u",
       "[BUILD]/scripts/slave/runtest.py",
       "--target",
       "Release",
       "--xvfb",
       "--factory-properties",
       "{\"blamelist\": [\"cool_dev1337@chromium.org\", \"hax@chromium.org\"], \"branch\": \"\", \"build_config\": \"Release\", \"buildername\": \"linux_chromium_rel_swarming\", \"buildnumber\": 571, \"issue\": 12853011, \"mastername\": \"tryserver.chromium\", \"patchset\": 1, \"project\": \"chrome\", \"recipe\": \"chromium_trybot\", \"repository\": \"\", \"requester\": \"commit-bot@chromium.org\", \"revision\": null, \"rietveld\": \"https://codereview.chromium.org\", \"root\": \"src\", \"slavename\": \"TestSlavename\", \"workdir\": \"/path/to/workdir/TestSlavename\"}",
       "--build-properties",
       "{\"blamelist\": [\"cool_dev1337@chromium.org\", \"hax@chromium.org\"], \"branch\": \"\", \"build_config\": \"Release\", \"buildername\": \"linux_chromium_rel_swarming\", \"buildnumber\": 571, \"issue\": 12853011, \"mastername\": \"tryserver.chromium\", \"patchset\": 1, \"project\": \"chrome\", \"recipe\": \"chromium_trybot\", \"repository\": \"\", \"requester\": \"commit-bot@chromium.org\", \"revision\": null, \"rietveld\": \"https://codereview.chromium.org\", \"root\": \"src\", \"slavename\": \"TestSlavename\", \"workdir\": \"/path/to/workdir/TestSlavename\"}",
       "--annotate=gtest",
       "--test-type=telemetry_perf_unittests",
       "--builder-name=linux_chromium_rel_swarming",
       "--slave-name=TestSlavename",
       "--build-number=571",
       "--run-python-script",
       "[SLAVE_BUILD]/src/tools/perf/run_tests",
-      "--browser=release"
+      "--browser=release",
+      "--write-full-results-to",
+      "/path/to/tmp/json"
     ],
     "name": "telemetry_perf_unittests (with patch)"
   },
   {
     "cmd": [
       "python",
       "-u",
       "[SLAVE_BUILD]/src/chrome/test/nacl_test_injection/buildbot_nacl_integration.py",
       "--mode",
       "Release",
@@ skipping 58 matching lines @@
       "https://chromium-swarm.appspot.com",
       "--shards",
       "5",
       "--decorate",
       "--print-status-updates",
       "browser_tests (with patch)/Linux/[dummy hash for browser_tests]/linux_chromium_rel_swarming/571"
     ],
     "name": "[swarming] browser_tests (with patch)"
   }
 ]