Remove deprecated managed policy arn ref

[richgreen-moj]

We get persistent warnings that managed_policy_arn is deprecated.

Replace this with resource aws_iam_role_policy_attachment in response to deployment warnings:

│ Warning: Argument is deprecated
│ 
│   with module.baseline.module.ec2_instance["t1-ncr-db-1-a"].aws_iam_role.this,
│   on .terraform/modules/baseline.ec2_instance/main.tf line 343, in resource "aws_iam_role" "this":
│  343:   managed_policy_arns = var.instance_profile_policies
│ 
│ The managed_policy_arns argument is deprecated. Use the
│ aws_iam_role_policy_attachment resource instead. If Terraform should
│ exclusively manage all managed policy attachments (the current behavior of
│ this argument), use the aws_iam_role_policy_attachments_exclusive resource
│ as well.

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Setting default tflint config...
Running tflint --init...
Installing "terraform" plugin...
Installed "terraform" (source: github.com/terraform-linters/tflint-ruleset-terraform, version: 0.9.1)
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Setting default tflint config...
Running tflint --init...
Installing "terraform" plugin...
Installed "terraform" (source: github.com/terraform-linters/tflint-ruleset-terraform, version: 0.9.1)
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CTFLint Scan Success

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*****************************

Setting default tflint config...
Running tflint --init...
Installing "terraform" plugin...
Installed "terraform" (source: github.com/terraform-linters/tflint-ruleset-terraform, version: 0.9.1)
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CTFLint Scan Success

Show Output

*****************************

Setting default tflint config...
Running tflint --init...
Installing "terraform" plugin...
Installed "terraform" (source: github.com/terraform-linters/tflint-ruleset-terraform, version: 0.9.1)
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[ep-93]

Looks all good, but calling it 'this' can we have a better name?

[richgreen-moj]

I think if we change that it'd make sense to do a bigger overhaul of the module as I was just following the naming convention applied to most of the resources in this module. Perhaps that'd be a separate PR?

Also that could possibly cause all users upgrading to need to rebuild their resources just for the name change.

[ep-93]

Comments addressed, approved!