Improve lifecycle of ZenModeFragment & friends

* Don't keep Settings observers longer than start-stop.
* Only call updateState() once on controllers during create->start->resume.
* Remove some duplicate controller update methods from ZenModesFragmentBase (we can directly call DashboardFragment's).
* Don't update controllers if unrelated modes were changed.
* Extract ZenSettingsObserver for use in the link tile later.
* Add tests.

Fixes: 353946788
Test: atest com.android.settings.notification.modes
Flag: android.app.modes_ui
Change-Id: I64b51714d699b5c3a592a76fcb615d2999998829

src/com/android/settings/notification/modes/ZenModeFragment.java

@@ -79,14 +79,6 @@ public class ZenModeFragment extends ZenModeFragmentBase {
         return prefControllers;
     }
 
-    @Override
-    public void onAttach(@NonNull Context context) {
-        super.onAttach(context);
-
-        // allow duration preference controller to listen for settings changes
-        use(ManualDurationPreferenceController.class).registerSettingsObserver();
-    }
-
     @Override
     public void onStart() {
         super.onStart();
@@ -99,6 +91,9 @@ public class ZenModeFragment extends ZenModeFragmentBase {
             mModeMenuProvider = new ModeMenuProvider(mode);
             activity.addMenuProvider(mModeMenuProvider);
         }
+
+        // allow duration preference controller to listen for settings changes
+        use(ManualDurationPreferenceController.class).registerSettingsObserver();
     }
 
     @Override
@@ -106,13 +101,8 @@ public class ZenModeFragment extends ZenModeFragmentBase {
         if (getActivity() != null) {
             getActivity().removeMenuProvider(mModeMenuProvider);
         }
-        super.onStop();
-    }
-
-    @Override
-    public void onDetach() {
         use(ManualDurationPreferenceController.class).unregisterSettingsObserver();
-        super.onDetach();
+        super.onStop();
     }
 
     @Override
@@ -122,13 +112,13 @@ public class ZenModeFragment extends ZenModeFragmentBase {
     }
 
     @Override
-    protected void updateZenModeState() {
+    protected void onUpdatedZenModeState() {
         // Because this fragment may be asked to finish by the delete menu but not be done doing
         // so yet, ignore any attempts to update info in that case.
         if (getActivity() != null && getActivity().isFinishing()) {
             return;
         }
-        super.updateZenModeState();
+        super.onUpdatedZenModeState();
     }
 
     private class ModeMenuProvider implements MenuProvider {