do not check file types too early.

a check was added to ensure that file types are not mixed in
built artifacts but the check was running too early, potentially
checking files that are not closed or even exists which can create
false positive.

Bug: 172550678
Test: Existing

Change-Id: I1c2cd8566751e5cdb318bc5ee1472d4c1ad8f3e2
3 files changed