[AppService] Fix - bug that prevented changing Container settings in Set-AzWebApp and Set-AzWebAppSlot

[vinisoto]

Description

-Fix - bug that prevented changing Container settings in Set-AzWebApp and Set-AzWebAppSlot
-Fixed typos.

Checklist

• I have read the Submitting Changes section of CONTRIBUTING.md
• The title of the PR is clear and informative
• The appropriate ChangeLog.md file(s) has been updated:
  • For any service, the ChangeLog.md file can be found at src/{{SERVICE}}/{{SERVICE}}/ChangeLog.md
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• The PR does not introduce breaking changes
• If applicable, the changes made in the PR have proper test coverage
• For public API changes to cmdlets:
  • a cmdlet design review was approved for the changes in this repository (Microsoft internal only)
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[VeryEarly]

Please add test case for these changes

[vinisoto]

@VeryEarly - Added test cases.

FYI @jvano @panchagnula

[Kotasudhakarreddy]

@vinisoto - what was the scenario to move siteConfig configuration update to behind the appSettings configuration update. It is reported as regression issue in #14998 . please let me whether I can alter their sequence of updating the configuration or it should be like this for any of the other functionality.

[vinisoto]

We need to make sure that the app settings below are updated before or at the same time as WindowsFxVersion (which is in SiteConfig). Otherwise, server side validation for WindowsFxVersion will fail since it will be trying to use "old" container settings.

public const string DockerRegistryServerUrl = "DOCKER_REGISTRY_SERVER_URL";
public const string DockerRegistryServerUserName = "DOCKER_REGISTRY_SERVER_USERNAME";
public const string DockerRegistryServerPassword = "DOCKER_REGISTRY_SERVER_PASSWORD";

[Kotasudhakarreddy]

@vinisoto - For now I have reverted your changes. Because it has created a lot of mess in just few days. can you give me the #GitID for the same. I want to analyze it further to understand the issue and fix it if required.

@panchagnula - FYI.

[panchagnula]

@Kotasudhakarreddy we should make sure to fix the issue Vini was working on as well with your changes so that we don't trade one regression for another. i.e this bug #13866

[Kotasudhakarreddy]

@vinisoto - I have reverted your changes only from WebsitesClient.cs->UpdateWebAppConfiguration method. But I don't see any server side validation for setting WindowsFxVersion. Could you please test this PR and confirm us the same.