Make all the rest of the recipes explicitly specify GIT_MODE

scripts/slave/recipes/custom_tabs_client.expected/basic.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[depot_tools::bot_update]/resources/bot_update.py",
       "--master",
       "master.tryserver.client.custom_tabs_client",
       "--builder",
       "linux",
       "--slave",
       "linux_slave",
       "--spec",
-      "cache_dir = '[GIT_CACHE]'\nsolutions = [{'deps_file': 'DEPS', 'managed': True, 'name': 'custom_tabs_client', 'url': 'https://chromium.googlesource.com/external/github.com/GoogleChrome/custom-tabs-client.git'}]",
+      "cache_dir = '[GIT_CACHE]'\nsolutions = [{'deps_file': '.DEPS.git', 'managed': True, 'name': 'custom_tabs_client', 'url': 'https://chromium.googlesource.com/external/github.com/GoogleChrome/custom-tabs-client.git'}]",
       "--root",
       "custom_tabs_client",
       "--revision_mapping_file",
       "{\"custom_tabs_client\": \"got_revision\"}",
       "--git-cache-dir",
       "[GIT_CACHE]",
       "--output_json",
       "/path/to/tmp/json",
       "--revision",
       "custom_tabs_client@HEAD",
@@ skipping 43 matching lines @@
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]"
     },
     "name": "gclient runhooks"
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]