Put ApkVerityTest in vts-core

VTS provides rootable environment for ApkVerityTest to run.
ApkVerityTest needs to write block device to verify the failure case of
fs-verity.

Test: see ApkVerityTests and block_device_writer in `unzip -l
      out/host/linux-x86/vts-core/android-vts-core.zip`
Bug: 150641206
Change-Id: Idc71907a28f68fc873c5cac940aa706e0b79843e