Adding swagger for endpoint certificates#17156

ruowan merged 3 commits intoAzure:dev-sql-Microsoft.Sql-2021-11-01-previewAzure/azure-rest-api-specs:dev-sql-Microsoft.Sql-2021-11-01-previewfrom

srmarkov:dev/srmarkov/EndpointCertificatesArmsrmarkov/azure-rest-api-specs:dev/srmarkov/EndpointCertificatesArmCopy head branch name to clipboard