Add public cloud cosmos endpoint suffix (Azure#27307)

Co-authored-by: Ben Broderick Phillips <bebroder@microsoft.com>

Author: azure-sdk

eng/common/TestResources/clouds/AzureCloud.json

@@ -2,6 +2,7 @@
     "azureAuthorityHost": "https://login.microsoftonline.com/",
     "cognitiveServicesEndpointSuffix": ".cognitiveservices.azure.com",
     "communicationServicesEndpointSuffix": ".communication.azure.com",
+    "cosmosEndpointSuffix": "cosmos.azure.com",
     "keyVaultDomainSuffix": ".vault.azure.net",
     "keyVaultEndpointSuffix": ".vault.azure.net",
     "storageEndpointSuffix": "core.windows.net"