Check if storage app data and obb directories exist in vold

As storage is not mounted in system server, we use vold
to check if storage app data and obb directories exist instead.

We add a method in vold so it only creates app data and obb dirs
if dirs do not exist to speed up app starting time.

Bug: 160336374
Test: Data and obb directories are created when a new app is started
Change-Id: I1bd784d9c9e05463f71433fc782ac4e0c831cbf1
5 files changed