Create new 30g heap elasticsearch workers

Temporarily leave the old node names in place with an override to
16g heap size, but pass the openstack_project default of 30g into
the elasticsearch module as a new variable. Also don't actually
configure the new servers to install and run elasticsearch yet,
since there are manual steps needed to prep the additional block
devices on them.

Change-Id: I9fca2115c8996ae2f1a6c605bcdf16a8b6342a24
Merge "Create new 30g heap elasticsearch workers"