Add chz to OWNERS file

Bug: 132637962
diff --git a/OWNERS b/OWNERS
index be5f88c..a607e72 100644
--- a/OWNERS
+++ b/OWNERS
@@ -1,3 +1,4 @@
 fbarchard@google.com
 phoglund@google.com
 magjed@google.com
+chz@google.com