fix: managed identity not being enabled for nodes

[comtalyst]

Fixes #197

Description
We currently hardcode managed identity enablement for AKS node bootstrapping script to be false, which is incorrect as we need it to be true per our managed identity support. This PR is a quick fix for this. See the linked issue for a consequence of this bug.

How was this change tested?

• Manually in NAP environment by assigning acrpull role to the kubelet identity and compare the results before and after the fix. This role assignment should be equivalent to attach-acr.

Does this change impact docs?

• Yes, PR includes docs updates
• Yes, issue opened: #
• No

Release Note

- Fix an issue where provisioned node(s) do not have permission to pull images from Azure Container Registry (ACR) for pods even after integrating with the cluster

[coveralls]

Pull Request Test Coverage Report for Build 8352364991

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 97.716%

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Totals
Change from base Build 8352358991:	0.0%
Covered Lines:	35591
Relevant Lines:	36423

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💛 - Coveralls

[tallaxes]

Let's also make sure to develop E2E test to cover this

[comtalyst]

Let's also make sure to develop E2E test to cover this

#221 will address this