infra/publish_tarball: move export_tarball.py to recipes

scripts/slave/recipes/infra/publish_tarball.expected/basic.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]/scripts/slave/bot_update.py",
       "--master",
       "chromium.testing.master",
       "--builder",
       "TestBuilder",
@@ skipping 48 matching lines @@
       "@@@SET_BUILD_PROPERTY@got_v8_revision_cp@\"refs/heads/master@{#43426}\"@@@",
       "@@@SET_BUILD_PROPERTY@got_swarming_client_revision_cp@\"refs/heads/master@{#276089}\"@@@",
       "@@@SET_BUILD_PROPERTY@got_webrtc_revision_cp@\"refs/heads/master@{#120644}\"@@@",
       "@@@SET_BUILD_PROPERTY@got_revision_cp@\"refs/heads/master@{#170242}\"@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
-      "[SLAVE_BUILD]/src/tools/export_tarball/export_tarball.py",
-      "--help"
-    ],
-    "name": "export_tarball.py --help",
-    "stdout": "/path/to/tmp/"
-  },
-  {
-    "cmd": [
-      "python",
-      "-u",
-      "[SLAVE_BUILD]/src/tools/export_tarball/export_tarball.py",
+      "RECIPE_MODULE[chromium]/resources/export_tarball.py",
       "--remove-nonessential-files",
       "chromium-38.0.2125.122",
       "--verbose",
       "--progress"
     ],
     "cwd": "[TMP_BASE]/export_tarball_tmp_1",
     "name": "export_tarball"
   },
   {
     "cmd": [
@@ skipping 26 matching lines @@
       "@@@STEP_LOG_LINE@python.inline@@@@",
       "@@@STEP_LOG_LINE@python.inline@import os, sys@@@",
       "@@@STEP_LOG_LINE@python.inline@from common import chromium_utils@@@",
       "@@@STEP_LOG_LINE@python.inline@@@@",
       "@@@STEP_LOG_LINE@python.inline@if os.path.exists(sys.argv[1]):@@@",
       "@@@STEP_LOG_LINE@python.inline@  chromium_utils.RemoveDirectory(sys.argv[1])@@@",
       "@@@STEP_LOG_END@python.inline@@@"
     ]
   }
 ]