Fix CMDUploadTestCase in presubmit

Bug: 1025293
Change-Id: I41ca2fba3855ecad3036e94a3bdc39b399c1a276
Recipe-Nontrivial-Roll: build_limited_scripts_slave
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1918609
Commit-Queue: Anthony Polito <apolito@google.com>
Auto-Submit: Anthony Polito <apolito@google.com>
Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>

tests/git_cl_test.py

@@ -3349,6 +3349,7 @@ class CMDUploadTestCase(CMDTestCaseBase):
     mock.patch('git_cl.fetch_try_jobs').start()
     mock.patch('git_cl._trigger_try_jobs', return_value={}).start()
     mock.patch('git_cl.Changelist.CMDUpload', return_value=0).start()
+    mock.patch('git_cl.Settings.GetIsGerrit', return_value=True).start()
     self.addCleanup(mock.patch.stopall)
 
   def testUploadRetryFailed(self):