Add sub owner to common/split and tests

Test: n/a
Bug: 207582920
Change-Id: I46cc309b2453296910c8516cffd2b5b352376b01
diff --git a/libs/WindowManager/Shell/tests/OWNERS b/libs/WindowManager/Shell/tests/OWNERS
index f4efc37..1c28c3d 100644
--- a/libs/WindowManager/Shell/tests/OWNERS
+++ b/libs/WindowManager/Shell/tests/OWNERS
@@ -6,3 +6,4 @@
 lbill@google.com
 madym@google.com
 hwwang@google.com
+chenghsiuchang@google.com