* add_kms_key_id: Allow user to supply their own kms_key_id

Change-Id: I23d1288851301328afaa61686b42d8376d303415

* Updated README.md
Co-authored-by: Andy Hibbert <anhibber@cisco.com>
Co-authored-by: actions-bot <58130806+actions-bot@users.noreply.github.com>