recipe_modules/chromite: Use "build_type".

scripts/slave/recipes/cros/cbuildbot.expected/chromiumos_coverage.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",
       "--revision_mapping_file",
       "{}",
       "--git-cache-dir",
       "[GIT_CACHE]",
       "--output_json",
       "/path/to/tmp/json",
       "--revision",
-      "chromite@factory-1412.B:",
+      "chromite@firmware-uboot_v2-1299.B:",
       "--output_manifest"
     ],
     "env": {
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]"
     },
     "name": "bot_update",
     "~followup_annotations": [
       "@@@STEP_TEXT@Some step text@@@",
       "@@@STEP_LOG_LINE@json.output@{@@@",
       "@@@STEP_LOG_LINE@json.output@  \"did_run\": true, @@@",
       "@@@STEP_LOG_LINE@json.output@  \"fixed_revisions\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@    \"chromite\": \"factory-1412.B:\"@@@",
+      "@@@STEP_LOG_LINE@json.output@    \"chromite\": \"firmware-uboot_v2-1299.B:\"@@@",
       "@@@STEP_LOG_LINE@json.output@  }, @@@",
       "@@@STEP_LOG_LINE@json.output@  \"manifest\": {}, @@@",
       "@@@STEP_LOG_LINE@json.output@  \"patch_failure\": false, @@@",
       "@@@STEP_LOG_LINE@json.output@  \"patch_root\": \"chromite\", @@@",
       "@@@STEP_LOG_LINE@json.output@  \"properties\": {}, @@@",
       "@@@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@@@"
     ]
   },
   {
     "allow_subannotations": true,
     "cmd": [
       "[SLAVE_BUILD]/chromite/buildbot/cbuildbot",
       "--buildroot",
       "[ROOT]/cbuild/external_master",
       "--buildbot",
       "--branch",
-      "factory-1412.B",
+      "firmware-uboot_v2-1299.B",
       "--buildnumber",
       "0",
       "--chrome_rev",
       "stable",
       "--debug",
       "--clobber",
       "--config_repo",
-      "https://fake.googlesource.com/myconfig/repo.git",
+      "https://example.com/repo.git",
       "--repo-cache",
       "/var/cache/chrome-infra/ccompute-setup/cros-internal",
       "x86-generic-full"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "cbuildbot [x86-generic-full]"
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]