Generating DNS client from latest Swagger changes

[muwaqar]

Description

Generating DNS client from latest Swagger changes (Azure/azure-rest-api-specs#2656). Turns out that there was no code changes required because the previous PR (#4109) included those changes already. So this PR is mainly updating the dns_resource-manager.txt file.

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[dsgouda]

LGTM
Ran the .cmd command locally to check for diffs but could not find any. Still needs investigation as to why the original PR had all the code generated correctly