OWNERS: allow copybara to update common.mk automatically

BUG=None
TEST=CQ passes

Change-Id: Ia8ad40ce70bdfbb7e7a27515d9fc36f0d9605222
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/frecon/+/6457636
Tested-by: Mike Frysinger <[email protected]>
Commit-Queue: Mike Frysinger <[email protected]>
Reviewed-by: Dominik Behr <[email protected]>
diff --git a/OWNERS b/OWNERS
index b687c45..4faecad 100644
--- a/OWNERS
+++ b/OWNERS
@@ -1 +1,4 @@
 [email protected]
+
+# Robots.
+per-file common.mk = file:chromiumos/owners:v1:/bots/OWNERS.copybara