Disable verity metadata for eng builds

We don't have dm-verity enabled on eng builds, so don't waste time
generating metadata for images.

Change-Id: Ib2c8d459bb50c30dc32a4ea1fdedc152c09a3a0f
(cherry picked from commit beae6395fc934ae24955a5e96ec04cda5535d952)
1 file changed