[Express Route] Added Support for IPv6 Circuit Connection Configuration.

[amwate]

Latest improvements:

Below changes to ExpressRouteCircuitConfig are to provide the support for IPv6 properties.
The support was added to NRP in the September release. Although the feature was not published or GA'd.

The below configurations would add a node IPv6CircuitConnectionProperties to the existing expressRouteCircuitConnection object.

The above block would be used by all the northbound clients like azure-powershell/ azcli/terraform/portal.

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[azure-pipelines]

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[azure-pipelines]

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[azure-pipelines]

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[anton-evseev]

Please address ModelValidation errors
https://dev.azure.com/azure-sdk/public/_build/results?buildId=233338&view=logs&jobId=8d2f9c49-cd83-5a9d-f3fe-2fd651afa742

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[MikhailTryakhov]

Hey @amwate, we are close to release our monthly branch. In case you won't solve all the failed jobs/get ARM approval - your PR would be closed around midnight today.

[azure-pipelines]

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[v-shhatt]

reviewed.. please fix errors

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Azure Pipelines could not run because the pipeline triggers exclude this branch/path.

[anton-evseev]

network-december-release has been already merged to meep tight deadlines. If your PR is urgent, please retarget to master

[azure-pipelines]

Azure Pipelines could not run because the pipeline triggers exclude this branch/path.

[amwate]

network-december-release has been already merged to meep tight deadlines. If your PR is urgent, please retarget to master

It is not urgent. We can retarget it to network-january-release when it is pulled.

[amwate]

Hey @amwate, we are close to release our monthly branch. In case you won't solve all the failed jobs/get ARM approval - your PR would be closed around midnight today.

Sure no problem. We can targe this in the next release.

[MikhailTryakhov]

Closing per latest comment