def transform_params(params_in):
    """
    Args:
        params_in (dict): Python dict of input params e.g.
        {
            "principal_role": "$[alfred_ssm_/org/primary/service_catalog/principal/role_arn]"
        }

    Return:
        params_out (list): Python list of output params e.g.
        {
            "ParameterKey": "principal_role",
            "ParameterValue": "$[alfred_ssm_/org/primary/service_catalog/principal/role_arn]"
        }
    """
    params_list = []
    for key, value in params_in.items():
        param = {}
        param.update({"ParameterKey": key})
        param.update({"ParameterValue": value})
        params_list.append(param)
    return params_list