Add OWNERS for VTS module vts_core_liblp_test

Each VTS module is required to have OWNERS file. The ownership is based on
go/vts-owners. For more information about ownership policy, please visit
go/xts-owners-policy.

Test: Tree Hugger
Bug: 143903671
Change-Id: I685d6fda211c9bce445d9fea351442b29541e639