recipe_modules/chromite: Use "build_type".

scripts/slave/recipes/cros/cbuildbot.expected/chromiumos_paladin.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[depot_tools::bot_update]/resources/bot_update.py",
       "--spec",
       "cache_dir = '[GIT_CACHE]'\nsolutions = [{'deps_file': '.DEPS.git', 'managed': True, 'name': 'chromite', 'url': 'https://chromium.googlesource.com/chromiumos/chromite.git'}]",
       "--patch_root",
       "chromite",
@@ skipping 25 matching lines @@
       "@@@STEP_LOG_LINE@json.output@  \"root\": \"chromite\", @@@",
       "@@@STEP_LOG_LINE@json.output@  \"step_text\": \"Some step text\"@@@",
       "@@@STEP_LOG_LINE@json.output@}@@@",
       "@@@STEP_LOG_END@json.output@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
+      "\nimport shutil\nimport sys\nshutil.copy(sys.argv[1], sys.argv[2])\n",
+      "[SLAVE_BUILD]/chromite/cbuildbot/config_dump.json",
+      "/path/to/tmp/json"
+    ],
+    "name": "read chromite config",
+    "~followup_annotations": [
+      "@@@STEP_LOG_LINE@config@{@@@",
+      "@@@STEP_LOG_LINE@config@  \"x86-generic-paladin\": {@@@",
+      "@@@STEP_LOG_LINE@config@    \"build_type\": \"paladin\"@@@",
+      "@@@STEP_LOG_LINE@config@  }@@@",
+      "@@@STEP_LOG_LINE@config@}@@@",
+      "@@@STEP_LOG_END@config@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "python",
+      "-u",
       "RECIPE_MODULE[build::gitiles]/resources/gerrit_client.py",
       "--json-file",
       "/path/to/tmp/json",
       "--url",
       "https://chromium.googlesource.com/chromiumos/manifest-versions/+/a94a8fe5ccb19ba61c4c0873d391e987982fbbd3",
       "--format",
       "json",
       "--attempts",
       "10"
     ],
@@ skipping 41 matching lines @@
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "cbuildbot [x86-generic-paladin]"
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]