Fix git_map_test.py

I think the latest Git version changed this behavior.

Change-Id: Id10c3ec41daf4e6700fc8168373cae9482502231
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/6422996
Commit-Queue: Allen Li <ayatane@chromium.org>
Feels: Yiwei Zhang <yiwzhang@google.com>
Reviewed-by: Yiwei Zhang <yiwzhang@google.com>

tests/git_map_test.py

@@ -74,7 +74,7 @@ class GitMapTest(git_test_utils.GitRepoReadOnlyTestBase):
 
     def testGitMap(self):
         expected = os.linesep.join([
-            '* 6e85e877ea	(tag_O, origin/main, origin/branch_O) 1970-01-30 ~ O',
+            '* 6e85e877ea	(tag_O, origin/main, origin/branch_O, origin/HEAD) 1970-01-30 ~ O',
             '* 4705470871	(tag_N) 1970-01-28 ~ N',
             '* 8761b1a94f	(tag_M) 1970-01-26 ~ M',
             '* 5e7ce08691	(tag_G) 1970-01-24 ~ G',