[git_cl] Add --global to creds-check

The UX of cd'ing to a non-Gerrit repo to setup common repo auth is not
good.  Also people don't read.

Bug: 408501013
Change-Id: Ia31914cf8672d0b5a6033de11c928140fd34a95c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/6442235
Reviewed-by: Gavin Mak <gavinmak@google.com>
Commit-Queue: Allen Li <ayatane@chromium.org>

git_cl.py

@@ -3900,7 +3900,12 @@ class _GitCookiesChecker(object):
 @metrics.collector.collect_metrics('git cl creds-check')
 def CMDcreds_check(parser, args):
     """Checks credentials and suggests changes."""
-    _, _ = parser.parse_args(args)
+    parser.add_option(
+        '--global',
+        action='store_true',
+        dest='force_global',
+        help='Check global credentials instead of for the current repo.')
+    options, args = parser.parse_args(args)
 
     if newauth.SwitchedOn():
         cl = Changelist()
@@ -3910,7 +3915,7 @@ def CMDcreds_check(parser, args):
             remote_url = ''
         wizard = git_auth.ConfigWizard(
             git_auth.UserInterface(sys.stdin, sys.stdout))
-        wizard.run(remote_url)
+        wizard.run(remote_url=remote_url, force_global=options.force_global)
         return 0
     if newauth.ExplicitlyDisabled():
         git_auth.ClearRepoConfig(os.getcwd(), Changelist())