PM-3349 Added custom window so that we can always get the current Active Window. This is used to support the Android Autofil and multi-window scenarios.

src/Core/ResumeWindow.cs

@@ -0,0 +1,45 @@
+namespace Bit.Core
+{
+    // This ResumeWindow is used as a Workaround for Android to be able to find the current "IsActive" Window
+    // It also allows setting a "PendingPage" on an existing Window which then navigates when the Window is active.
+    public class ResumeWindow : Window
+    {
+        public Page PendingPage {get;set;}
+        public bool IsActive { get; set; }
+
+        public ResumeWindow(Page page) : base(page) { }
+
+        /// <summary>
+        /// You need to do this inside OnActivated not OnResumed
+        /// Androids OnResume maps to OnActivated
+        /// Androids OnRestart is what Maps to OnResumed
+        /// I realize this is confusing from the perspective of Android
+        /// https://github.com/dotnet/maui/issues/1720 explains it a bit better
+        /// </summary>
+        protected override void OnActivated()
+        {
+            base.OnActivated();
+
+            if (PendingPage is not null)
+                Page = PendingPage;
+
+            PendingPage = null;
+            IsActive = true;
+        }
+
+        protected override void OnDeactivated()
+        {
+            IsActive = false;
+        }
+    }
+
+    public class MainAppWindow : ResumeWindow
+    {
+        public MainAppWindow(Page page) : base(page) { }
+    }
+
+    public class AutoFillWindow : ResumeWindow
+    {       
+        public AutoFillWindow(Page page) : base(page){ }
+    }
+}