linux-builder: Add ephemeral option to delete VM's disk image on service restart
#1211
| Job | Run time |
|---|---|
| 2m 30s | |
| 3m 48s | |
| 3m 43s | |
| 17m 31s | |
| 5m 59s | |
| 13m 56s | |
| 47m 27s |