Add jbires to system/security OWNERS

The number of times I've said "Oh yeah, I'll put a change in later to
add myself to OWNERS" has become embarassing.

Test: I can give OWNERS +2
Change-Id: If24b192fe0f2ca65f6cac58602c0b2b63f2df094
diff --git a/OWNERS b/OWNERS
index bb51005..4e214e8 100644
--- a/OWNERS
+++ b/OWNERS
@@ -4,3 +4,4 @@
 hasinitg@google.com
 kroot@google.com
 zeuthen@google.com
+jbires@google.com