[presubmit] Add check to call validation endpoint for config files

Bug:509672
Change-Id: I74bbaa725be829c625cd617c58b3e849acb18102
Reviewed-on: https://chromium-review.googlesource.com/726847
Commit-Queue: Mun Yong Jang <myjang@google.com>
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>
Reviewed-by: Nodir Turakulov <nodir@chromium.org>
diff --git a/git_common.py b/git_common.py
index 1bb5937..59a904b 100644
--- a/git_common.py
+++ b/git_common.py
@@ -954,6 +954,13 @@
   return ret
 
 
+def get_remote_url(remote='origin'):
+  try:
+    return run('config', 'remote.%s.url' % remote)
+  except subprocess2.CalledProcessError:
+    return None
+
+
 def upstream(branch):
   try:
     return run('rev-parse', '--abbrev-ref', '--symbolic-full-name',