OWNERS: Add nnk and remove dcashman

Bug: 114211287
Test: none
Change-Id: Ibbc83152cbd3535db2018d9c3d084a1c4190b33e
(cherry picked from commit 456e7806bcca703775c469fc4cf6ceeb450111b9)
diff --git a/sepolicy/OWNERS b/sepolicy/OWNERS
index 9d3f1b1..e6fbbd4 100644
--- a/sepolicy/OWNERS
+++ b/sepolicy/OWNERS
@@ -1,9 +1,9 @@
 alanstokes@google.com
 bowgotsai@google.com
-dcashman@google.com
 jbires@google.com
 jeffv@google.com
 jgalenson@google.com
+nnk@google.com
 sspatil@google.com
 tomcherry@google.com
 trong@google.com