Be more resistant to data volume corruption

Too many VM terminations and hard reboots would eventually corrupt
the user's data volume in strange ways (e.g., the home button would
stop working or the browser wouldn't start but everything else was
fine).

Added some extra mount options to /data and /cache to match physical
phones that use ext4 partitions. Also added e2fsck to the build which
it automatically run at mount-time if the volume was not cleanly
dismounted.

Bumped VM version number to 1.3.1.

Change-Id: I17b3235c17cce296d1adf558f9a77a24dbb25013