update OWNERS for vts related projects

Bug: none
Test: none
Change-Id: I2328d041836c10e9f90a032fc6a22917efb5fd58
diff --git a/OWNERS b/OWNERS
index 2f35d7f..b9d65ac 100644
--- a/OWNERS
+++ b/OWNERS
@@ -2,3 +2,4 @@
 wwtbuaa@google.com
 yim@google.com
 yuexima@google.com
+guangzhu@google.com