Widevine persistent data is stored in /data/mediadrm, HALs
are not allowed to access files in /data. Move persistent
data to /data/vendor/mediadrm/widevine for older devices,
and persistent data will not be saved under /data/vendor.
Test: Play Movies & Tv, Netflix
bug: 36601695
Change-Id: I31fdd43b7db327bf6d8343dc95e9883ae6bce70d
