Add patb@ as a owner of SystemConfig tests

Giving ownership of
    services/tests/servicestests/src/com/android/server/systemconfig/

Test: N/A
Change-Id: Ifae11b700bd5f2134cb7e31d50d02d204b649f7c
diff --git a/services/OWNERS b/services/OWNERS
index b7128a3..a083319 100644
--- a/services/OWNERS
+++ b/services/OWNERS
@@ -4,3 +4,4 @@
 per-file art-profile* = calin@google.com, ngeoffray@google.com, vmarko@google.com
 
 per-file java/com/android/server/* = toddke@google.com,patb@google.com
+per-file tests/servicestests/src/com/android/server/systemconfig/* = patb@google.com