Add xutan@ to WM shell owner

Also move the resource owners to the new OWNERS file from the OWNERS
file one level of folder above.

Bug: None
Test: None
Change-Id: I81b3eeff0cf565482772023243652a949cfbcd1f
diff --git a/libs/WindowManager/Shell/OWNERS b/libs/WindowManager/Shell/OWNERS
new file mode 100644
index 0000000..4b12590
--- /dev/null
+++ b/libs/WindowManager/Shell/OWNERS
@@ -0,0 +1,4 @@
+xutan@google.com
+
+# Give submodule owners in shell resource approval
+per-file res*/*/*.xml = hwwang@google.com, lbill@google.com, madym@google.com