Labs: Fix generation of meta_p.meta

The disapearance of slice separation on the database replicas
caused the meta table to be created without (almost all) entries
since the check for slice no longer had the necessary data.

This restores the field even though it is no longer meaningful
so that the table remains populated.

Bug: 54962
Change-Id: Ifcf67342063d47e33bd68267464268e6d36a92a1