autotest: use cidr notation from sync_cloudsql_access

BUG=chromium:811401
TEST=Local run of script

Change-Id: Id13482f0674f99c383780273de46e1a09a68b6ba
Reviewed-on: https://chromium-review.googlesource.com/915030
Commit-Ready: Aviv Keshet <akeshet@chromium.org>
Tested-by: Aviv Keshet <akeshet@chromium.org>
Reviewed-by: Dan Shi <dshi@google.com>
diff --git a/site_utils/sync_cloudsql_access.py b/site_utils/sync_cloudsql_access.py
index 64d72e8..14d77d8 100755
--- a/site_utils/sync_cloudsql_access.py
+++ b/site_utils/sync_cloudsql_access.py
@@ -91,12 +91,14 @@
             raise
     print '...Done: %s' % ips
 
+    cidr_ips = [str(ip) + '/32' for ip in ips]
+
     login = False
     while True:
         try:
             utils.run('gcloud config set project %s -q' % project)
             cmd = ('gcloud sql instances patch %s --authorized-networks %s '
-                   '-q' % (instance, ','.join(ips)))
+                   '-q' % (instance, ','.join(cidr_ips)))
             print 'Running command to update whitelists: "%s"' % cmd
             utils.run(cmd, stdout_tee=sys.stdout, stderr_tee=sys.stderr)
             return