Append some operations to boot from volume pattern

The follow operations added:
* Write content to a volume and check written content
* Boot a instance twice from a single volume

This patch rename the class name and the file name.
Because, the name brings a little confusion.
VolumeSnapshotPattern seems to do the test of snapshot only.

Change-Id: I549934c4cd412ac88961f113d037235cc177d3fd
Related-bug #1210437
3 files changed