GitLab

Apps without sdcard_r or sdcard_rw need to have someone create
package-specific directories on their behalf.  If apps have trouble
creating on their own, they now delegate through system to have
vold create the paths.

Requires that the requested path is actually managed by vold.

Bug: 10577808
Change-Id: I6835fc8f52240f9de07f89742a426a153e3ca32a