ecryptfs was dropped from RHEL/CentOS, use LUKS on a RAM-backed block
device (brd) instead.
Made the element name more generic
Added systemctl enable call in postinstall (for systemd init), so that
the service is correctly started and listed as wanted by amphora-agent
Change-Id: Id8c7ff93ae244ef14480e22c85dc79355a902105
Closes-Bug: #1642982
Closes-Bug: #1662952