ART: Update dex-file fallback code

Allow non-executable oat files when the boot image is out of
date.

(cherry picked from commit 9ea84d0b)

Bug: 73667005
Test: m test-art-host
Merged-In: Ib04339bd87fa5e268d0c636c98df62ee72d613c5
Change-Id: Ib04339bd87fa5e268d0c636c98df62ee72d613c5