Configure Amazon SSM Agent proxy setting

[mbloch1986]

In order to use the AMAZON SSM Agent when proxy is enabled during provisioning we need to configure the proxy settings for the AMAZON SSM Agent, so it can communicate back to AWS. Atm we are only installing it via packer-aem but we aren't setting the proxy configuration for it.

[mbloch1986]

This will be done as part of the baking process, to follow the already implemented process. As the proxy settings for the awslogs daemon is also already done during baking.

shinesolutions/packer-aem#175