webos-filesystem-paths: Add location of db8 media directory

:Release Notes:
Add additional directory for db8 in /media/cryptofs/data/db8/mediadb

:Detailed Notes:

:Testing Performed:
Compiled and tested locally

:QA Notes:

:Build Notes:
Invalidates all sstate signatures

:Issues Addressed:
[GF-51737] db8: Unhide directory /media/cryptofs/data/.db8

Open-webOS-DCO-1.0-Signed-off-by: Maksym Sditanov <maxim.sditanov@lge.com>
Change-Id: Ia46572cd0d6e971965af2185d344becf66e0598b
Reviewed-on: https://g2g.palm.com/3957
Reviewed-by: DCO Verification
Reviewed-by: Maksym Sditanov <maxim.sditanov@lge.com>
Tested-by: Maksym Sditanov <maxim.sditanov@lge.com>
Reviewed-by: Susan Montooth <susan.montooth@lge.com>