don't use /cache/dalvik-cache for now

Adding the property will fix the bootloop when trying to dexopt system.

Change-Id: I183b90d9c8ae6263d1853ffe29626acac2ce8cc8
Signed-off-by: Dirk Rettschlag <dirk.rettschlag@gmail.com>
Merge "don't use /cache/dalvik-cache for now" into kitkat