Adjust CompOS case

Make sure we verify the signatures on CompOS artifacts regardless of
what 'odrefresh --check' returns, and move the check first.

Also make sure we don't use invalid CompOS artifacts if we can't
delete them.

Restore check that all the artifacts that CompOS generated are still
present - this works now we do it before running odrefresh, and while
probably not technically necessary is reassuring.

Fix redundant map copy.

These changes are designed to work both with and without the new
--compilation-os-mode switch, and I've tested both scenarios.

Bug: 211458160
Test: Manual
Change-Id: Ie6a49ab64678329d096b0f0ae70cd966ba8b3bf1
Merged-In: Ie6a49ab64678329d096b0f0ae70cd966ba8b3bf1
3 files changed