Amend owner files for releasetool scripts

Test: th
Change-Id: Ia77586f634609e5f3a8868e7d1237776052aab30
diff --git a/tools/releasetools/OWNERS b/tools/releasetools/OWNERS
index d7fc540..9962836 100644
--- a/tools/releasetools/OWNERS
+++ b/tools/releasetools/OWNERS
@@ -1,4 +1,6 @@
 elsk@google.com
 nhdo@google.com
 xunchang@google.com
-zhaojiac@google.com
+
+per-file merge_*.py = danielnorman@google.com
+