Move persist entry to fstab and mount at /mnt/vendor/persist
Apply required user, group and permissions once persist
folder is created through __mount and parititon is mounted.
Run restorecon on /mnt/vendor/persist.
Change-Id: I20a16f3669bc7abf9844525c6ba0db1521a5a8e2
* To prevent property name collisions between properties of system and
vendor, 'vendor.' prefix must be added to a vendor HAL service name.
You can see the details in go/treble-sysprop-compatibility documents.
Test: succeeded building and tested on a sailfish device.
Bug: 36796459
Change-Id: I48e6ee0ae3fe401e39efb273256d991fac676357
