Set supported and current variant for WSL

Co-authored-by: Didier Roche <didrocks@ubuntu.com>

system_setup/client/client.py

@@ -28,6 +28,8 @@ class SystemSetupClient(SubiquityClient):
 
     snapd_socket_path = None
 
+    variant = "wsl_setup"
+
     controllers = [
         "Welcome",
         "WSLIdentity",
@@ -44,6 +46,7 @@ class SystemSetupClient(SubiquityClient):
         # 3. provide an API for this for the flutter UI to know about it
         # 4. Add Configuration Base page before Advanced
         # 5. Add language page
+        # self.variant = "wsl_configuration"
         if opts.reconfigure:
             self.controllers = [
                 "Welcome",

system_setup/server/server.py

@@ -34,6 +34,8 @@ class SystemSetupServer(SubiquityServer):
         "SetupShutdown",
     ]
 
+    supported_variants = ["wsl_setup", "wsl_configuration"]
+
     def make_model(self):
         root = '/'
         if self.opts.dry_run: