Fix notification intent flags

app/src/main/AndroidManifest.xml

@@ -293,9 +293,8 @@
 
     <activity
       android:excludeFromRecents="true"
-      android:launchMode="singleTask"
       android:name=".reminders.NotificationActivity"
-      android:taskAffinity=""
+      android:taskAffinity=":notification"
       android:theme="@style/TranslucentDialog"/>
 
     <activity android:name=".activities.NavigationDrawerCustomization" />

app/src/main/java/org/tasks/notifications/NotificationManager.java

@@ -1,7 +1,5 @@
 package org.tasks.notifications;
 
-import static android.content.Intent.FLAG_ACTIVITY_MULTIPLE_TASK;
-import static android.content.Intent.FLAG_ACTIVITY_NEW_TASK;
 import static androidx.core.app.NotificationCompat.FLAG_INSISTENT;
 import static androidx.core.app.NotificationCompat.FLAG_NO_CLEAR;
 import static com.google.common.collect.Iterables.concat;
@@ -371,11 +369,7 @@ public class NotificationManager {
             .setShowWhen(true)
             .setTicker(taskTitle);
 
-    final Intent intent = new Intent(context, NotificationActivity.class);
+    Intent intent = NotificationActivity.newIntent(context, taskTitle, id);
-    intent.setFlags(FLAG_ACTIVITY_NEW_TASK | FLAG_ACTIVITY_MULTIPLE_TASK);
-    intent.setAction("NOTIFY" + id); // $NON-NLS-1$
-    intent.putExtra(NotificationActivity.EXTRA_TASK_ID, id);
-    intent.putExtra(NotificationActivity.EXTRA_TITLE, taskTitle);
     builder.setContentIntent(
         PendingIntent.getActivity(context, (int) id, intent, PendingIntent.FLAG_UPDATE_CURRENT));
 

app/src/main/java/org/tasks/reminders/NotificationActivity.java

@@ -1,5 +1,6 @@
 package org.tasks.reminders;
 
+import android.content.Context;
 import android.content.Intent;
 import android.os.Bundle;
 import androidx.fragment.app.FragmentManager;
@@ -28,6 +29,14 @@ public class NotificationActivity extends InjectingAppCompatActivity
   @Inject TaskDaoBlocking taskDao;
   @Inject ThemeAccent themeAccent;
 
+  public static Intent newIntent(Context context, String title, long id) {
+    Intent intent = new Intent(context, NotificationActivity.class);
+    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
+    intent.putExtra(NotificationActivity.EXTRA_TASK_ID, id);
+    intent.putExtra(NotificationActivity.EXTRA_TITLE, title);
+    return intent;
+  }
+
   private long taskId;
   private CompositeDisposable disposables;
 
@@ -37,17 +46,7 @@ public class NotificationActivity extends InjectingAppCompatActivity
 
     themeAccent.applyStyle(getTheme());
 
-    setup(getIntent());
+    Intent intent = getIntent();
-  }
-
-  @Override
-  protected void onNewIntent(Intent intent) {
-    super.onNewIntent(intent);
-
-    setup(intent);
-  }
-
-  private void setup(Intent intent) {
 
     taskId = intent.getLongExtra(EXTRA_TASK_ID, 0L);