Remove the code for verifying artifacts.

Verifying artifacts using dexoptanalyzer takes long and is not suitable
for running at early boot. It was replaced with a faster approach, but
the code hasn't been cleaned up. As we are making more and more changes
to odrefresh, the code for verifying artifaccts is outdated and becomes
a maintenance burden.

Bug: 203198541
Test: Presubmits
Change-Id: Ie689a38f44c986582901c1589b31af41e769d13e
4 files changed