Switch to system/core/janitors as OWNERS.

Change-Id: I65527f5e7efebdcf1bba2852e516212918df12d8
diff --git a/OWNERS b/OWNERS
index d349d3a..7529cb9 100644
--- a/OWNERS
+++ b/OWNERS
@@ -1,4 +1 @@
-# Default code reviewers picked from top 3 or more developers.
-# Please update this list if you find better candidates.
-enh@google.com
-nnk@google.com
+include platform/system/core:/janitors/OWNERS