BT: Fix glob pattern in owners file

- */vts/* only matches one layer of directories
  e.g. a/vts/b is matched, a/b/vts/c is not matched
- **/vts/** matches everything up to a/b/c/vts/d/e/f

Test: make
Change-Id: I57ea4f2ab2fdeef5929895c7443a1d1097985dba