chore: update windows default VHD for August

[mainred]

Reason for Change:

This PR updates:

• aks-windows default VHD with August patch, together with hotfixes,
• WindowsServer version to the one released on August7th.

building VHD pipeline: https://dev.azure.com/AzureContainerUpstream/Kubernetes/_build/results?buildId=10572&view=results
push VHD to marketplace release: https://dev.azure.com/AzureContainerUpstream/Kubernetes/_releaseProgress?_a=release-pipeline-progress&releaseId=749

Issue Fixed:

Requirements:

• uses conventional commit messages
• includes documentation
• adds unit tests
• tested upgrade from previous version

Notes:

[jsturtevant]

It looks like the latest Windows Server image was published to the market place could you update the base image version as well at:

aks-engine/pkg/api/azenvtypes.go

Lines 195 to 200 in 49236ab

	WindowsServer2019OSImageConfig = AzureOSImageConfig{
	ImageOffer: "WindowsServer",
	ImageSku: "2019-Datacenter-Core-with-Containers-smalldisk",
	ImagePublisher: "MicrosoftWindowsServer",
	ImageVersion: "17763.1339.2007101755",
	}

The latest August image:

az vm image show --urn MicrosoftWindowsServer:WindowsServer:2019-Datacenter-Core-with-Containers-smalldisk:latest --query "name" 
"17763.1397.2008070242"

[mainred]

Updated windows-server version per James as well
ping @jsturtevant @AbelHu to take another look.

[jsturtevant]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[codecov]

Codecov Report

Merging #3730 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #3730   +/-   ##
=======================================
  Coverage   73.17%   73.17%           
=======================================
  Files         147      147           
  Lines       25322    25322           
=======================================
  Hits        18529    18529           
  Misses       5655     5655           
  Partials     1138     1138           

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[jsturtevant]

/lgtm

[jsturtevant]

/approve

[acs-bot]

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