build: Bot_update refactor recipe roll

scripts/slave/recipes/chromium.gpu.recipe_autogen.expected/Android_Debug__Nexus_6_.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[depot_tools::bot_update]/resources/bot_update.py",
-      "--master",
-      "chromium.gpu",
-      "--builder",
-      "Android Debug (Nexus 6)",
-      "--slave",
-      "TestSlave",
       "--spec",
       "cache_dir = '[ROOT]/git_cache'\nsolutions = [{'custom_deps': {'src/third_party/WebKit/LayoutTests': None}, 'custom_vars': {'googlecode_url': 'http://%s.googlecode.com/svn', 'llvm_url': 'http://llvm.org/svn/llvm-project', 'nacl_trunk': 'http://src.chromium.org/native_client/trunk', 'sourceforge_url': 'https://svn.code.sf.net/p/%(repo)s/code', 'webkit_trunk': 'http://src.chromium.org/blink/trunk'}, 'deps_file': '.DEPS.git', 'managed': True, 'name': 'src', 'url': 'https://chromium.googlesource.com/chromium/src.git'}]\ntarget_os = ['android']",
       "--root",
       "src",
       "--revision_mapping_file",
       "{\"src\": \"got_revision\", \"src/third_party/WebKit\": \"got_webkit_revision\", \"src/tools/swarming_client\": \"got_swarming_client_revision\", \"src/v8\": \"got_v8_revision\"}",
       "--git-cache-dir",
       "[GIT_CACHE]",
       "--output_json",
       "/path/to/tmp/json",
       "--revision",
       "src@HEAD",
-      "--force",
       "--output_manifest"
     ],
     "cwd": "[SLAVE_BUILD]",
     "env": {
       "PATH": "%(PATH)s:RECIPE_PACKAGE[depot_tools]"
     },
     "name": "bot_update",
     "~followup_annotations": [
       "@@@STEP_TEXT@Some step text@@@",
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ skipping 76 matching lines @@
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "slave_steps"
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]