Since we are using bash syntax in some of the element fragments,
we should make sure we use bash for all of them, so that things don't
break on systems where /bin/sh != /bin/bash.
Change-Id: If2f043c57aa4e1492b7f9839213ef6123f683612
Boots into the new image kernel once baremetal-deploy-helper signals
it is finished using kexec utilities.
Change-Id: I705787cc394ef14200d80404ee497762ab79b452