The current tasks only use a hardcoded list deploying only the required files.
When using multiple custom policies, additionnal object-*.builder and
object*.gz files are to be deployed as well.
This adds a new default-empty variable that can be overridden when needed

Change-Id: I29c8e349c7cc83e3a2e01ff702d235a0cd97340e
Closes-Bug: #1844752