Avoid recomputing the dex checksum during class loading

Thread the already computed checksum to VerifyOatAndDexFileChecksums and
LoadMultiDexFilesFromOatFile to avoid recomputing it.

Bug:17346103

(cherry picked from commit ca3459398018360d9968a52eebf727df085caf83)

Change-Id: Ie244efaca55b9e7c814b35feec7fce11fab3856d
2 files changed