Propagate Title to android and ios window

src/Core/src/Handlers/Window/WindowHandler.Android.cs

@@ -17,7 +17,8 @@ protected override void ConnectHandler(Activity platformView)
 			UpdateVirtualViewFrame(platformView);
 		}
 
-		public static void MapTitle(IWindowHandler handler, IWindow window) { }
+		public static void MapTitle(IWindowHandler handler, IWindow window) =>
+			handler.PlatformView.UpdateTitle(window);
 
 		public static void MapContent(IWindowHandler handler, IWindow window)
 		{

src/Core/src/Handlers/Window/WindowHandler.iOS.cs

@@ -12,14 +12,8 @@ protected override void ConnectHandler(UIWindow platformView)
 
 			UpdateVirtualViewFrame(platformView);
 		}
-
-		public static void MapTitle(IWindowHandler handler, IWindow window)
-		{
-#if MACCATALYST
-			if (handler.PlatformView.WindowScene is not null)
-				handler.PlatformView.WindowScene.Title = window.Title ?? String.Empty;
-#endif
-		}
+		public static void MapTitle(IWindowHandler handler, IWindow window) =>
+			handler.PlatformView.UpdateTitle(window);
 
 		public static void MapContent(IWindowHandler handler, IWindow window)
 		{

src/Core/src/Platform/Android/WindowExtensions.cs

@@ -9,6 +9,14 @@ namespace Microsoft.Maui
 {
 	public static partial class WindowExtensions
 	{
+		internal static void UpdateTitle(this Activity platformWindow, IWindow window)
+		{
+			if (string.IsNullOrEmpty(window.Title))
+				platformWindow.Title = ApplicationModel.AppInfo.Current.Name;
+			else
+				platformWindow.Title = window.Title;
+		}
+
 		internal static DisplayOrientation GetOrientation(this IWindow? window)
 		{
 			if (window == null)

src/Core/src/Platform/iOS/WindowExtensions.cs

@@ -9,6 +9,15 @@ namespace Microsoft.Maui.Platform
 {
 	public static partial class WindowExtensions
 	{
+		internal static void UpdateTitle(this UIWindow platformWindow, IWindow window)
+		{
+			// If you set the title to null the app will crash
+			// If you set it to an empty string the title reverts back to the 
+			// default app title.
+			if (OperatingSystem.IsIOSVersionAtLeast(13) && platformWindow.WindowScene is not null)
+				platformWindow.WindowScene.Title = window.Title ?? String.Empty;
+		}
+
 		internal static void UpdateX(this UIWindow platformWindow, IWindow window) =>
 			platformWindow.UpdateUnsupportedCoordinate(window);
 

src/Core/tests/DeviceTests/Handlers/Window/WindowHandlerTests.Android.cs

@@ -0,0 +1,31 @@
+using System.Threading.Tasks;
+using AndroidX.AppCompat.App;
+using Microsoft.Maui.Controls;
+using Xunit;
+
+namespace Microsoft.Maui.DeviceTests
+{
+	public partial class WindowHandlerTests : CoreHandlerTestBase
+	{
+		[Fact]
+		public async Task TitleSetsOnWindow()
+		{
+			await InvokeOnMainThreadAsync(() =>
+			{
+				var activity = (AppCompatActivity)MauiProgramDefaults.DefaultContext;
+				var testWindow = new Window();
+
+				Assert.True(activity is not null, "Activity is Null");
+
+				testWindow.Title = "Test Title";
+				WindowExtensions.UpdateTitle(activity, testWindow);
+
+				Assert.Equal("Test Title", activity.Title);
+				testWindow.Title = null;
+
+				WindowExtensions.UpdateTitle(activity, testWindow);
+				Assert.Equal(activity.Title, ApplicationModel.AppInfo.Current.Name);
+			});
+		}
+	}
+}