Unprovision iso ramdisk boot from test

The boot_iso ramdisk test unfortunately has been discovered to
orphan occupied "nodes" after the test has executed. This change
triggers the test to send a command to force the node to be
unprovisioned at the end of the test.

Closes-Bug: 2055469
Change-Id: Ib525fe099d5884f442cdc375c5a8d230710d20a4
1 file changed