[Android] Fix user data dropped after upgrade from crosswalk 8

Because of multiple profile support, from crosswalk 9 user data
will be put under profile's subfolder.
We need to consider the case that crosswalk upgrades from 8 to 9.
For such case, detect the first launch and move the previous user
data to profile's subfolder.

BUG=https://crosswalk-project.org/jira/browse/XWALK-3252
Sorry for forget mention const just now