update OWNERS for vts related projects

Bug: none
Test: none
Change-Id: I857bf34a7989da1b5514e0128dbd9ce26b7bde85
diff --git a/OWNERS b/OWNERS
index 17c17c9..97df5d9 100644
--- a/OWNERS
+++ b/OWNERS
@@ -1,3 +1,4 @@
 yim@google.com
 zhuoyao@google.com
 yuexima@google.com
+guangzhu@google.com