At IAlloc backend guess state from admin state

At IAlloc backend guess state from admin state

At the IAlloc backend of htools we do not get the actual
state of the instance (as everything is state-of-record only).
However, we do get the administrative state. Therefore, by
assuming that for each instance the actual state is the one
corresponding to the administrated one, we can get a much better
description of the cluster than blindly assuming all instances
are running. Do so, whenever the admin_state is provided.

Signed-off-by: Klaus Aehlig <aehlig@google.com>
Reviewed-by: Lisa Velden <velden@google.com>