[AutoPR track2_@azure/arm-network] Add AppGw swagger changes for L4 proxy#7351

Draft

openapi-sdkautomation[bot] wants to merge 1 commit intomainfrom sdkAuto/17561/track2_@azure_arm-network

+629-108

Commits on Jan 31, 2022

CodeGen from PR 17561 in Azure/azure-rest-api-specs
SDKAuto
committed