Add test to verify instance bootability after volume snapshot

This patch adds a test to ensure an instance can boot
from a bootable volume after a snapshot is created while
the instance is in a stopped state. The issue being
validated impacts volumes that use an NFS backend,
causing boot failures post-snapshot creation.

Related-bug: #1989514
Change-Id: I2e09b5b0fc6b49cb64cfcbe4394121741e0df3ed
1 file changed