gsutil: use depot_tools.gsutil_py_path instead of path['depot_tools']

scripts/slave/recipes/chromium.expected/amp_split_recipe_trigger_failure.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[depot_tools::bot_update]/resources/bot_update.py",
       "--master",
       "chromium.fyi",
       "--builder",
       "Android Tests (amp split)",
@@ skipping 522 matching lines @@
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
     },
     "name": "spawn_device_monitor"
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[build::gsutil]/resources/gsutil_wrapper.py",
       "--",
-      "[DEPOT_TOOLS]/gsutil.py",
+      "RECIPE_PACKAGE_REPO[depot_tools]/gsutil.py",
       "----",
       "cp",
       "gs://chrome-amp-keys/commit_queue_pool/api_key",
       "[BUILD]/site_config/.amp_commit_queue_pool_key"
     ],
     "env": {
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json",
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
     },
     "name": "gsutil download amp api key"
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[build::gsutil]/resources/gsutil_wrapper.py",
       "--",
-      "[DEPOT_TOOLS]/gsutil.py",
+      "RECIPE_PACKAGE_REPO[depot_tools]/gsutil.py",
       "----",
       "cp",
       "gs://chrome-amp-keys/commit_queue_pool/api_secret",
       "[BUILD]/site_config/.amp_commit_queue_pool_secret"
     ],
     "env": {
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json",
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
     },
     "name": "gsutil download amp api secret"
@@ skipping 1884 matching lines @@
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
     },
     "name": "logcat_dump"
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[build::gsutil]/resources/gsutil_wrapper.py",
       "--",
-      "[DEPOT_TOOLS]/gsutil.py",
+      "RECIPE_PACKAGE_REPO[depot_tools]/gsutil.py",
       "--force-version",
       "4.7",
       "-o",
       "GSUtil:parallel_composite_upload_threshold=50M",
       "----",
       "cp",
       "[SLAVE_BUILD]/src/out/Release/full_log",
       "gs://chromium-android/logcat_dumps/Android Tests (amp split)/77457"
     ],
     "env": {
@@ skipping 56 matching lines @@
       "@@@STEP_LOG_LINE@python.inline@  os.remove(report)@@@",
       "@@@STEP_LOG_END@python.inline@@@"
     ]
   },
   {
     "name": "$result",
     "reason": "7 tests failed: ['AndroidWebViewTest', 'ContentShellTest', 'ChromePublicTest', 'ChromeSyncShellTest', 'junit_unit_tests', 'chrome_junit_tests', 'content_junit_tests']",
     "status_code": 1
   }
 ]