Add redis ordering with ceilometer-central

Add redis ordering with ceilometer-central

This is another missing constraint. The `require-all=false` part is good
to have, otherwise Ceilometer (and transitively Heat) would switch to
A/P mode. However, at the moment `require-all=false` isn't a recognized
parameter on Fedora, hence the logic fork based on $::operatingsystem.

Change-Id: I2657087192a05b2d8f0ab04ec60631d35331bf6c