[Android] Clamp BottomNavigationView MaxItemCount to 5 for Material3 net11.0 compatibility

src/Controls/src/Core/Compatibility/Handlers/Shell/Android/ShellItemRenderer.cs

@@ -176,7 +176,8 @@ protected virtual BottomSheetDialog CreateMoreBottomSheet(Action<int, BottomShee
 
 			// handle the more tab
 			var items = ((IShellItemController)ShellItem).GetItems();
-			for (int i = _bottomView.MaxItemCount - 1; i < items.Count; i++)
+			var maxItems = Math.Min(_bottomView.MaxItemCount, BottomNavigationViewUtils.MaxBottomNavigationItems);
+			for (int i = maxItems - 1; i < items.Count; i++)
 			{
 				var closure_i = i;
 				var shellContent = items[i];
@@ -376,7 +377,7 @@ protected override void OnShellSectionPropertyChanged(object sender, PropertyCha
 				var index = ((IShellItemController)ShellItem).GetItems().IndexOf(shellSection);
 
 				var itemCount = ((IShellItemController)ShellItem).GetItems().Count;
-				var maxItems = _bottomView.MaxItemCount;
+				var maxItems = Math.Min(_bottomView.MaxItemCount, BottomNavigationViewUtils.MaxBottomNavigationItems);
 				IMenuItem menuItem = null;
 
 				if (!(itemCount > maxItems && index > maxItems - 2))

src/Controls/src/Core/Platform/Android/BottomNavigationViewUtils.cs

@@ -27,6 +27,15 @@ public static class BottomNavigationViewUtils
 	{
 		internal const int MoreTabId = 99;
 
+		/// <summary>
+		/// Maximum number of items allowed in the bottom navigation bar.
+		/// Newer versions of the Xamarin.Google.Android.Material package report
+		/// <c>BottomNavigationView.MaxItemCount</c> as 6, whereas older versions returned 5.
+		/// Clamped to 5 for consistent behavior regardless of the Material library version.
+		/// See https://github.com/dotnet/maui/pull/33450
+		/// </summary>
+		internal const int MaxBottomNavigationItems = 5;
+
 		public static Drawable CreateItemBackgroundDrawable()
 		{
 			var stateList = ColorStateList.ValueOf(Colors.Black.MultiplyAlpha(0.2f).ToPlatform());
@@ -71,6 +80,7 @@ internal static async void SetupMenu(
 			BottomNavigationView bottomView,
 			IMauiContext mauiContext)
 		{
+			maxBottomItems = Math.Min(maxBottomItems, MaxBottomNavigationItems);
 			Context context = mauiContext.Context;
 
 			while (items.Count < menu.Size())
@@ -162,7 +172,7 @@ public static BottomSheetDialog CreateMoreBottomSheet(
 			IMauiContext mauiContext,
 			List<(string title, ImageSource icon, bool tabEnabled)> items)
 		{
-			return CreateMoreBottomSheet(selectCallback, mauiContext, items, 5);
+			return CreateMoreBottomSheet(selectCallback, mauiContext, items, MaxBottomNavigationItems);
 		}
 
 		internal static BottomSheetDialog CreateMoreBottomSheet(
@@ -171,6 +181,7 @@ internal static BottomSheetDialog CreateMoreBottomSheet(
 			List<(string title, ImageSource icon, bool tabEnabled)> items,
 			int maxItemCount)
 		{
+			maxItemCount = Math.Min(maxItemCount, MaxBottomNavigationItems);
 			var context = mauiContext.Context;
 			var bottomSheetDialog = new BottomSheetDialog(context);
 			var bottomSheetLayout = new LinearLayout(context);
@@ -300,4 +311,4 @@ public static void SetShiftMode(this BottomNavigationView bottomNavigationView,
 			}
 		}
 	}
-}
+}