Add notification cancellation methods to background thread

Author: aurimasc

com.unity.mobile.notifications/Runtime/Android/Plugins/com/unity/androidnotifications/UnityNotificationBackgroundThread.java

@@ -16,6 +16,26 @@ public void enqueueTask(Runnable task) {
         mTasks.add(task);
     }
 
+    public void enqueueCancelNotification(int id) {
+        mTasks.add(() -> {
+            UnityNotificationManager.cancelPendingNotificationIntent(UnityNotificationManager.mUnityNotificationManager.mContext, id);
+        });
+    }
+
+    public void enqueueCancelAllNotifications() {
+        mTasks.add(() -> {
+            Context context = UnityNotificationManager.mUnityNotificationManager.mContext;
+            Set<String> ids = UnityNotificationManager.getScheduledNotificationIDs(context);
+
+            if (ids.size() > 0) {
+                for (String id : ids) {
+                    UnityNotificationManager.cancelPendingNotificationIntent(context, Integer.valueOf(id));
+                    UnityNotificationManager.deleteExpiredNotificationIntent(context, id);
+                }
+            }
+        });
+    }
+
     public void enqueueHousekeeping() {
         mTasks.add(() -> { performHousekeeping(); });
     }

com.unity.mobile.notifications/Runtime/Android/Plugins/com/unity/androidnotifications/UnityNotificationManager.java

@@ -571,22 +571,7 @@ public boolean checkIfPendingNotificationIsRegistered(int id) {
 
     // Cancel all the pending notifications.
     public void cancelAllPendingNotificationIntents() {
-        Set<String> ids;
-        synchronized (UnityNotificationManager.class) {
-            ids = this.getScheduledNotificationIDs(mContext);
-            saveScheduledNotificationIDs(mContext, new HashSet<>());
-        }
-
-        if (ids.size() > 0) {
-            Context context = mContext;
-            mBackgroundThread.enqueueTask(() -> {
-                for (String id : ids) {
-                    cancelPendingNotificationIntent(context, Integer.valueOf(id));
-                    deleteExpiredNotificationIntent(context, id);
-                }
-                triggerHousekeeping();
-            });
-        }
+        mBackgroundThread.enqueueCancelAllNotifications();
     }
 
     protected static synchronized Set<String> getScheduledNotificationIDs(Context context) {
@@ -603,10 +588,7 @@ private static synchronized void saveScheduledNotificationIDs(Context context, S
 
     // Cancel a pending notification by id.
     public void cancelPendingNotification(int id) {
-        synchronized (UnityNotificationManager.class) {
-            UnityNotificationManager.cancelPendingNotificationIntent(mContext, id);
-            triggerHousekeeping();
-        }
+        mBackgroundThread.enqueueCancelNotification(id);
     }
 
     // Cancel a pending notification by id.