Disable in-place vdex update

Vdex files can be corrupted by dexlayout or by previously dexlayout-ed
files being recompiled if they are used as both input and output.
Disable this feature.

Bug: 38113240
Test: OTA and dexopt
Change-Id: Iee2d9a6c1ba8cddda25290f68f50649d5288d588
(cherry picked from commit e446fede)