Ansible uri module HEADER_ parameters used in first_steps are deprecated

[babl-timandrews]

first_steps role breaks on HEADER_ parameters in call to uri module.
As of Ansible module v2.1 the HEADER_ parameters passed to the uri module are deprecated. We have just installed Ansible 2.9.10 and they have been removed (not sure what version removed them). The new requirements are to build a yaml hash, i.e.,
headers:
Accept: application/json

https://docs.ansible.com/ansible/2.3/uri_module.html shows the HEADER_ parameters being deprecated and https://docs.ansible.com/ansible/latest/modules/uri_module.html shows they are removed altogether.