Add support for resizing root volume

[mahdi-torabi]

This PR adds support for resizing root volume when launching an EC2 instance.

Limitations:

• AMI used for launching instance must support EBS as root volume otherwise the action fails with an error indicating this requirement

# sudo df -h 
Filesystem      Size  Used Avail Use% Mounted on
devtmpfs         16G     0   16G   0% /dev
tmpfs            16G     0   16G   0% /dev/shm
tmpfs            16G  412K   16G   1% /run
tmpfs            16G     0   16G   0% /sys/fs/cgroup
/dev/nvme0n1p1  128G  3.8G  125G   3% /

# sudo lsblk
/dev/nvme0n1p1  128G  3.8G  125G   3% /
NAME          MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
nvme0n1       259:0    0  128G  0 disk 
|-nvme0n1p1   259:1    0  128G  0 part /
`-nvme0n1p128 259:2    0    1M  0 part 

[mahdi-torabi]

Verified that volumes are automatically deleted after instance terminates.