[storagediscovery] Update client.tsp for csharp (#36351)

Co-authored-by: Shane Fu <[email protected]>
Co-authored-by: Ray Chen <[email protected]>

Author: 3 people

specification/storagediscovery/Microsoft.StorageDiscovery.Management/client.tsp

@@ -19,3 +19,8 @@ using Microsoft.StorageDiscovery;
   "StorageDiscoveryMgmtClient",
   "python"
 );
+
+@@clientName(Azure.ResourceManager.ResourceProvisioningState,
+  "StorageDiscoveryProvisioningState",
+  "csharp"
+);