Encode quickening info in .vdex.

We quicken vdex files for performance reasons, but when taking an OTA,
we need to revert the quickening to the original instructions. As vdex
should be independent of the oat file and oat file versions, we encode
the quickening data in the vdex.

test: m test-art-host-jit m test-art-host-gtest
bug:30937355

Change-Id: I9a543a161b70aa1cff99f8fe6f5b5cab7a6c4d31