Make rebase and sync the default for Gerrit updates

recipe_modules/bot_update/example.expected/gerrit_rebase_patch_ref.json

Index: recipe_modules/bot_update/example.expected/gerrit_rebase_patch_ref.json
diff --git a/recipe_modules/bot_update/example.expected/gerrit_rebase_patch_ref.json b/recipe_modules/bot_update/example.expected/gerrit_rebase_patch_ref.json
deleted file mode 100644
index 2d4257e772f4d1bbcedab0492b946fd359075d4a..0000000000000000000000000000000000000000
--- a/recipe_modules/bot_update/example.expected/gerrit_rebase_patch_ref.json
+++ /dev/null
@@ -1,44 +0,0 @@
-[
-  {
-    "cmd": [
-      "python",
-      "-u",
-      "RECIPE_MODULE[depot_tools::bot_update]/resources/bot_update.py",
-      "--master",
-      "experimental",
-      "--builder",
-      "Experimental Builder",
-      "--slave",
-      "somehost",
-      "--spec",
-      "cache_dir = '[GIT_CACHE]'\nsolutions = [{'deps_file': '.DEPS.git', 'managed': True, 'name': 'src', 'url': 'https://chromium.googlesource.com/chromium/src.git'}]",
-      "--root",
-      "src",
-      "--revision_mapping_file",
-      "{\"src\": \"got_cr_revision\"}",
-      "--git-cache-dir",
-      "[GIT_CACHE]",
-      "--output_json",
-      "/path/to/tmp/json",
-      "--revision",
-      "src@HEAD",
-      "--gerrit_rebase_patch_ref"
-    ],
-    "env": {
-      "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]"
-    },
-    "name": "bot_update",
-    "~followup_annotations": [
-      "@@@STEP_LOG_LINE@json.output@{@@@",
-      "@@@STEP_LOG_LINE@json.output@  \"did_run\": false, @@@",
-      "@@@STEP_LOG_LINE@json.output@  \"patch_failure\": false@@@",
-      "@@@STEP_LOG_LINE@json.output@}@@@",
-      "@@@STEP_LOG_END@json.output@@@"
-    ]
-  },
-  {
-    "name": "$result",
-    "recipe_result": null,
-    "status_code": 0
-  }
-]