Consume rgw_enable and mon_enable parameters to set the 'enable'
state for the systemd units.
Also removes support for sysvinit as we don't support Hammer
in the master branch so we can default to systemd.
Change-Id: I1e0415f0b7f640b1b2d05abcc2e7781ad5bb35a3
Closes-Bug: 1622825
Co-Authored-By: Alex Schultz <aschultz@redhat.com>