Add PreResolved strings dex cache array

For app images, this dex cache may be prepopulated to speed up
application startup. This new dex cache array is created when
--resolve-startup-const-strings=true.

Test: test-art-host
Bug: 116059983
Bug: 118385560

Change-Id: I379dc15174281665d7f4ceb106f7fbf51f89b921