DO NOT MERGE - Remove data dirs if a new install fails dexopt.

We'd otherwise leave the data dirs & native libraries
lying around. This will leave the app permanently broken
because the next install of the app will fail with
INSTALL_FAILED_UID_CHANGED.

Also remove an unnecessary instance variable.

Cherry-pick from master
Bug 13416059

Change-Id: I1e644aab74d5ea519231800915b39c2f55d043ae