{AKS} revert to use old region mapping

[bragi92]

Currently talking across multiple teams to align with one consistent naming experience.

Description

Reverting the changes made in this PR: #16377 since we're currently talking with the LA, AppInsights and Alerts team and bringing consistency to the naming experience for the new regions.

Testing Guide

History Notes

[Component Name 1] BREAKING CHANGE: az command a: Make some customer-facing breaking change.
[Component Name 2] az command b: Add some customer-facing feature.

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[bragi92]

@fengzhou-msft Reverting the changes made in this PR: #16377 since the shortcode mapping list I was following was not consistent. I'll create another PR to update this with the new regions once we have a consistent naming convention.

[yungezz]

@fengzhou-msft Reverting the changes made in this PR: #16377 since the shortcode mapping list I was following was not consistent. I'll create another PR to update this with the new regions once we have a consistent naming convention.

hi @bragi92 could you pls have someone else to review this since this pure business logic? thanks

[bragi92]

@fengzhou-msft Can you have a look at this PR? Its reverting the change I made in #16377 since we're still talking with the other teams (I should have the new PR ready by end of this week)

Also do you know how I can run the build pipeline again ~ the PR title wasn't properly formatted but I've fixed it now.