Find7: remove discard argument from fstab

Change-Id: Ibf317591e62d0b42f6f1fd9261d575a51b8ff952
Find7: fix usb disk for Kitkat vold

Change-Id: Ie723fb1ec4c9fa85971e0d879dfcc2fd4557ff00
Find7: update storage configuration for kitkat

As per https://source.android.com/devices/tech/storage/config.html,
set correct vold arguments in fstab, according to our overlay defines.

Also align ramfs storage device handling to N1, since both devices
neither use emulated sdcards nor do they need those directories.

Enable fuse deamon to handle our storage devices in kitkat (from N1).

Change-Id: I05e34621f83f6e4d174d33c3b3b0f0e46aa805c7