Merge pull request #3552 from BaronGreenback/NotificationFix

Fixes #3551 (Notifications Serialization error)

(cherry picked from commit 944fdb4c621fa2b65e970554d4e4daf7841a7a93)
Signed-off-by: Joshua M. Boniface <joshua@boniface.me>

MediaBrowser.Model/Notifications/NotificationOption.cs

@@ -1,3 +1,4 @@
+#pragma warning disable CA1819 // Properties should not return arrays
 #pragma warning disable CS1591
 
 using System;
@@ -9,21 +10,27 @@ namespace MediaBrowser.Model.Notifications
         public NotificationOption(string type)
         {
             Type = type;
+            DisabledServices = Array.Empty<string>();
+            DisabledMonitorUsers = Array.Empty<string>();
+            SendToUsers = Array.Empty<string>();
+        }
 
+        public NotificationOption()
+        {
             DisabledServices = Array.Empty<string>();
             DisabledMonitorUsers = Array.Empty<string>();
             SendToUsers = Array.Empty<string>();
         }
 
-        public string Type { get; set; }
+        public string? Type { get; set; }
 
         /// <summary>
-        /// User Ids to not monitor (it's opt out).
+        /// Gets or sets user Ids to not monitor (it's opt out).
         /// </summary>
         public string[] DisabledMonitorUsers { get; set; }
 
         /// <summary>
-        /// User Ids to send to (if SendToUserMode == Custom)
+        /// Gets or sets user Ids to send to (if SendToUserMode == Custom).
         /// </summary>
         public string[] SendToUsers { get; set; }