docs: update aws volume tagging policies details (#688)

docs/infracost_cloud/tagging_policies.md

@@ -74,10 +74,8 @@ Tagging policies check all AWS, Azure and Google Terraform resources that suppor
 
 - For `aws_autoscaling_group`, if the `propagate_at_launch` attribute is not set to true, the resource fails tagging policies as resources launched from those Auto Scaling groups will not get the required tags.
 - For `aws_instance` with `ebs_block_device` or `root_block_device` definitions, tags for the attached volumes are checked as follows:
-  - if `volume_tags` attribute is set it is checked. Otherwise,
-  - if there is at least one `ebs_block_device` and no `*_block_device.tags` set, `volume_tags` are checked. Otherwise,
-  - `.tags` for each `*_block_device` are checked.
-  - provider `default_tags` are automatically applied to `volume_tags` unless you are using an AWS provider version earlier than `5.39`.
+  - if `volume_tags` attribute is set it is checked. Otherwise, `.tags` for the `root_block_device` and each `ebs_block_device` are checked.
+  - provider `default_tags` are automatically applied to each `*_block_device.tags` (or `volume_tags`, if used) unless you are using an AWS provider version earlier than `5.39`.
 - For `aws_launch_template`, the `tag_specifications` attribute is also checked. If the `resource_type` is `instance` or `volume` these tags are then associated with either the `aws_instance` or `aws_autoscaling_group` resource that references the `aws_launch_template` and checked as part of those resources.
 - The `propagate_tags` attribute is checked for any resource that requires that to be set for tags to propagate to dynamically created resources: `aws_ecs_service`, `aws_scheduler_schedule`, `aws_batch_job_definition`, `aws_dynamodb_table`, `aws_pipes_pipe`, and `aws_cloudwatch_event_target`.
 - The following individual tag resources are not checked as these are used to tag resources defined outside of Terraform: `aws_autoscaling_group_tag`, `aws_ec2_tag`, `aws_transfer_tag`, `aws_ecs_tag`, `aws_dynamodb_tag`.