Revert "Removed app config code from ServiceClientAdapter"

This reverts commit fc38c44.

Author: mkherani

src/ResourceManager/RecoveryServices.Backup/Commands.RecoveryServices.Backup.ServiceClientAdapter/ServiceClientAdapter.cs

@@ -24,17 +24,26 @@ namespace Microsoft.Azure.Commands.RecoveryServices.Backup.Cmdlets.ServiceClient
 {
     public partial class ServiceClientAdapter
     {
+        const string AppSettingsSectionName = "appSettings";
         const string RecoveryServicesResourceNamespace = "Microsoft.RecoveryServices";
+        const string ProviderNamespaceKey = "ProviderNamespace";
         const string AzureFabricName = "Azure";
 
         ClientProxy<RecoveryServicesNS.RecoveryServicesBackupManagementClient, RecoveryServicesModelsNS.CustomRequestHeaders> BmsAdapter;
 
         public ServiceClientAdapter(SubscriptionCloudCredentials creds, Uri baseUri)
         {
+            System.Configuration.Configuration exeConfiguration = System.Configuration.ConfigurationManager.OpenExeConfiguration(System.Reflection.Assembly.GetExecutingAssembly().Location);
+            System.Configuration.AppSettingsSection appSettings = (System.Configuration.AppSettingsSection)exeConfiguration.GetSection(AppSettingsSectionName);
+            string recoveryServicesResourceNamespace = RecoveryServicesResourceNamespace;
+            if (appSettings.Settings[ProviderNamespaceKey] != null)
+            {
+                recoveryServicesResourceNamespace = appSettings.Settings[ProviderNamespaceKey].Value;
+            }
             BmsAdapter = new ClientProxy<RecoveryServicesNS.RecoveryServicesBackupManagementClient, RecoveryServicesModelsNS.CustomRequestHeaders>(
                 clientRequestId => new RecoveryServicesModelsNS.CustomRequestHeaders() { ClientRequestId = clientRequestId },
                                        creds, baseUri);
-            BmsAdapter.Client.ResourceNamespace = RecoveryServicesResourceNamespace;
+            BmsAdapter.Client.ResourceNamespace = recoveryServicesResourceNamespace;
         }
     }
 }