fix: set create_iam_policies default to false

[maxsxu]

Motivation

The create_iam_policies is going to be deprecated as we do not allow iam:CreatePolicy in terraform-managed-cloud.

Modifications

set create_iam_policies default to false

Verifying this change

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• Added integration tests for end-to-end deployment with large payloads (10MB)
• Extended integration test for recovery after broker failure

Documentation

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[github-actions]

@maxsxu:Thanks for your contribution. For this PR, do we need to update docs?
(The PR template contains info about doc, which helps others know more about the changes. Can you provide doc-related info in this and future PR descriptions? Thanks)