fix: ImmersiveMode, WebViewSoftInputPatch cause incorrect interface height

Author: Yu-Core

src/MauiBlazorToolkit/MauiBlazorToolkit/Platform/WebViewSoftInput/WebViewSoftInput.android.cs

@@ -1,4 +1,5 @@
 using Android.Content.Res;
+using Android.Views;
 using Android.Widget;
 using System.Runtime.Versioning;
 using static Android.Resource;
@@ -59,7 +60,14 @@ static int ComputeUsableHeight()
     {
         Rect rect = new Rect();
         MChildOfContent?.GetWindowVisibleDisplayFrame(rect);
-        return rect.Bottom - GetStatusBarHeight();
+        if(IsImmersiveMode())
+        {
+            return rect.Bottom;
+        }
+        else
+        {
+            return rect.Bottom - GetStatusBarHeight();
+        }
     }
 
     static int GetStatusBarHeight()
@@ -73,4 +81,12 @@ static int GetStatusBarHeight()
         }
         return result;
     }
+
+    static bool IsImmersiveMode()
+    {
+        var window = Activity.Window ?? throw new InvalidOperationException("Activity Window can't be null.");
+        View decorView = window.DecorView;
+        int uiOptions = (int)decorView.SystemUiVisibility;
+        return (uiOptions & (int)SystemUiFlags.Immersive) == (int)SystemUiFlags.Immersive;
+    }
 }