Greeter: Fix "settings were loaded" notification always being displayed

... even on the first boot after creating the Persistent Storage, which
should not actually load any settings (see the comment in the code
explaining why this happened).

config/chroot_local-includes/usr/lib/python3/dist-packages/tailsgreeter/ui/main_window.py

@@ -186,8 +186,21 @@ class GreeterMainWindow(Gtk.Window, TranslatableWindow):
         settings_loaded = False
         for setting in reversed(list(self.settings.region_settings)):
             try:
-                setting.load()
-                settings_loaded = True
+                changed = setting.load()
+                if changed:
+                    # We only want to show the "settings loaded" notification
+                    # if settings were actually changed, i.e. the settings
+                    # in the persistent settings dir were not the same as
+                    # the already configured ones.
+                    # Else, the notification would also be shown the first time
+                    # the system is booted after creating the Persistent Storage
+                    # (which currently means that the Persistent Storage is empty,
+                    # but that's WIP on #11529), because then the persistent
+                    # settings dir doesn't exist yet, which means that live-boot
+                    # copies the current settings dir to the Persistent Storage -
+                    # which contains the currently configured settings, which are
+                    # then loaded.
+                    settings_loaded = True
             except SettingNotFoundError as e:
                 logging.debug(e)
                 # The settings file does not exist, so we create it by
@@ -202,7 +215,7 @@ class GreeterMainWindow(Gtk.Window, TranslatableWindow):
                 # it has the default value.
                 if changed:
                     self.add_setting(setting.id)
-                settings_loaded = True
+                    settings_loaded = True
             except SettingNotFoundError as e:
                 logging.debug(e)
                 # The settings file does not exist, so we create it by

config/chroot_local-includes/usr/lib/python3/dist-packages/tailsgreeter/ui/region_settings.py

@@ -61,14 +61,19 @@ class LocalizationSettingUI(GreeterSetting):
         self._setting.save(self.value, is_default=False)
         super().apply()
 
-    def load(self):
+    def load(self) -> bool:
         try:
             value, is_default = self._setting.load()
         except SettingNotFoundError:
             raise
+
+        if value == self.value:
+            return False
+
         self.value = value
         self.value_changed_by_user = not is_default
         self.apply()
+        return True
 
     @property
     def default(self) -> {str, None}:
@@ -179,13 +184,15 @@ class LanguageSettingUI(LocalizationSettingUI):
         self._setting.apply_language(self.value)
         self.changed_cb(self.value)
 
-    def load(self):
+    def load(self) -> bool:
         try:
-            super().load()
+            changed = super().load()
         except SettingNotFoundError:
             raise
-        self._setting.apply_language(self.value)
-        self.changed_cb(self.value)
+        if changed:
+            self._setting.apply_language(self.value)
+            self.changed_cb(self.value)
+        return changed
 
 
 class FormatsSettingUI(LocalizationSettingUI):