Fix dex file reading in VdexFile::GetNextDexFileData.

Dex files in a vdex file are always aligned.

bug: 64527414
Test: run-test --random-profile 663-odd-dex-size

(cherry picked from commit 28453cf27c4f6ec194203a0227fbb5302d8c93f0)

Change-Id: If856c1594fab08a32b22cabfd94c6e45b48b5688
17 files changed