This reverts commit 2d7f8f4a47.
Avi sayeth:
"Isn't this the other way round? EBS is persistent."
and
"The patch is wrong too. Instance store takes 5 minutes to boot
compared to 1 minute for EBS."
Edit variables.json and run dist/ami/build_ami.sh, it will build & upload AMI.
When deploying the AMI, be sure to add two more disks(sdb, sdc) to construct RAID.