Update cos-patch trailer for main branch

Change-Id: I9b70eb3d89ef03b14263748dfac6f01dcf858368

PRESUBMIT.cfg

diff --git a/PRESUBMIT.cfg b/PRESUBMIT.cfg
index bdf4185..6b7b1c7 100644
--- a/PRESUBMIT.cfg
+++ b/PRESUBMIT.cfg
@@ -2,6 +2,9 @@
 cros lint = ../../chromite/bin/cros lint ${PRESUBMIT_FILES}
 
 [Hook Overrides]
+# Make sure cos_patch trailer is present
+cos_patch_trailer_check: true
+
 # Make sure Manifest files are valid.
 manifest_check: true