fix(settings): fix on theme change crash

This fixes such bug by only registering for listening to events on the onCreate method, and not on the onViewCreated method. For some wacky reason, when the activity gets recreated, the onViewCreated method runs again, but the onDestroy method doesn't, which makes the fragment register for events twice without unregistering, which causes the app to crash. Also refactors some duplicate code.

mastodon/src/main/java/org/joinmastodon/android/fragments/settings/AboutFragment.java

@@ -123,21 +123,6 @@ public class AboutFragment extends SettingsBaseFragment{
         if (list.findViewHolderForAdapterPosition(items.indexOf(checkForUpdateItem)) instanceof TextViewHolder tvh) tvh.rebind();
     }
 
-    @Override
-    public void onViewCreated(View view, Bundle savedInstanceState) {
-        super.onViewCreated(view, savedInstanceState);
-        if (GithubSelfUpdater.needSelfUpdating()) {
-            E.register(this);
-        }
-    }
-
-    @Override
-    public void onDestroy() {
-        super.onDestroy();
-        if (GithubSelfUpdater.needSelfUpdating())
-            E.unregister(this);
-    }
-
     private void clearImageCache(){
         MastodonAPIController.runInBackground(()->{
             Activity activity=getActivity();

mastodon/src/main/java/org/joinmastodon/android/fragments/settings/SettingsBaseFragment.java

@@ -33,6 +33,7 @@ import androidx.recyclerview.widget.LinearLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
 
 import org.joinmastodon.android.DomainManager;
+import org.joinmastodon.android.E;
 import org.joinmastodon.android.GlobalUserPreferences;
 import org.joinmastodon.android.MastodonApp;
 import org.joinmastodon.android.R;
@@ -93,6 +94,9 @@ public abstract class SettingsBaseFragment extends MastodonToolbarFragment imple
 		instanceName = UiUtils.getInstanceName(accountID);
 		DomainManager.getInstance().setCurrentDomain(session.domain + "/settings");
 
+		if (GithubSelfUpdater.needSelfUpdating())
+			E.register(this);
+
 		addItems(items);
 		title = getArguments().getString("title", getTitle().toString());
 		items.add(0, new GiantHeaderItem(title));
@@ -506,6 +510,7 @@ public abstract class SettingsBaseFragment extends MastodonToolbarFragment imple
 	}
 
 	protected void restartActivityToApplyNewTheme(){
+		onDestroy();
 		getActivity().recreate();
 	}
 
@@ -515,6 +520,10 @@ public abstract class SettingsBaseFragment extends MastodonToolbarFragment imple
 		if(needUpdateNotificationSettings && PushSubscriptionManager.arePushNotificationsAvailable()){
 			AccountSessionManager.getInstance().getAccount(accountID).getPushSubscriptionManager().updatePushSettings(pushSubscription);
 		}
+
+		if (GithubSelfUpdater.needSelfUpdating())
+			E.unregister(this);
+
 		if(needAppRestart) UiUtils.restartApp();
 	}
 

mastodon/src/main/java/org/joinmastodon/android/fragments/settings/SettingsMainFragment.java

@@ -59,19 +59,4 @@ public class SettingsMainFragment extends SettingsBaseFragment {
             Toast.makeText(getActivity(), getString(R.string.mo_update_available, GithubSelfUpdater.getInstance().getUpdateInfo().version), Toast.LENGTH_SHORT).show();
         }
     }
-
-    @Override
-    public void onViewCreated(View view, Bundle savedInstanceState) {
-        super.onViewCreated(view, savedInstanceState);
-        if (GithubSelfUpdater.needSelfUpdating()) {
-            E.register(this);
-        }
-    }
-
-    @Override
-    public void onDestroy() {
-        super.onDestroy();
-        if (GithubSelfUpdater.needSelfUpdating())
-            E.unregister(this);
-    }
 }