Skip the UbuntuAdvantage screen until we can validate the token

Signed-off-by: Olivier Gayot <olivier.gayot@canonical.com>

subiquity/client/controllers/ubuntu_advantage.py

@@ -35,6 +35,11 @@ class UbuntuAdvantageController(SubiquityTuiController):
 
     async def make_ui(self) -> UbuntuAdvantageView:
         """ Generate the UI, based on the data provided by the model. """
+
+        # TODO remove these two lines to enable this screen
+        await self.endpoint.skip.POST()
+        raise Skip("Hiding the screen until we can validate the token.")
+
         path_lsb_release: Optional[str] = None
         if self.app.opts.dry_run:
             # In dry-run mode, always pretend to be on LTS