Computing the compressed size of the cluster state on every invocation
of cluster:monitor/state action is expensive, and the value of this
field is dubious anyway. Therefore we want to remove computing this
field. As a first step, we stop computing and return this field by
default. To avoid breaking users, we will give them a system property to
use to tide them over until the next major release when we will actually
remove this field. This comes with a deprecation warning too, and the
backport to the appropriate minor will also include a note in the
migration guide. There will be a follow-up to remove this field in the
next major version.