The current method of installing the distribution packages required is
set in the tasks and cannot be changed by a deployer.
Currently the apt task always installs the latest package. This results
in unexpected binary changes when a deployer may simply be trying to
execute a configuration change.
This patch adds the ability for a deployer to change the desired state
so that the results are predictable.
Change-Id: I3732efabfa4fc7e80a8f172abd1415fd54489763
62bcac9f04