Do not use block_verify on target-files where feature is missing.

This will only be used when the block file format is at least
version 3.  For V1/V2 (L, L MR1) block versions, fall back to
the old range_sha1 check.

Bug: 19357591
Change-Id: I7cb178b70d48ec3c98cdb88ed1c94cf7797a01d0
(cherry picked from commit cad78c12)
Ticket: RENDANG-473