make VtsHalHidlTestUtils vendor_available so vts tests can be vendor: true. am: f6327d1122 am: bc05d3537b

Original change: https://googleplex-android-review.googlesource.com/c/platform/test/vts/+/18452396

Change-Id: Iad1be6d118707e8c18a32c572c48500676866691
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>