WPF Splashscreen doesn't work correctly on monitors with different dpi's

* .NET Core Version: 5.0
* Windows version: Windows 10 21H1
* Does the bug reproduce also in WPF for .NET Framework 4.8?: No
* Is this bug related specifically to tooling in Visual Studio (e.g. XAML Designer, Code editing, etc...)? No

**Problem description:**

Default SplashScreen image appears initially at wrong dpi in the center of the screen. It it then corrects the DPI and then is no longer in the center of the screen. So on a DPI higher than 100%, it appears to shrink and move off center.

**Actual behavior:**

SplashScreen appears at wrong DPI and then corrects itself (shrinks) and is moved off center.

**Expected behavior:**

SplashScreen appears at correct DPI and remains in the center of the screen.

**Minimal repro:**

1. Using a monitor that is set at a DPI higher than 100% (I was using 250%)
2. Create a Net Framework 5.0 WPF Application
3. Add an Image to the project
4. Set the Properties of the Image to BuildAction = SplashScreen
5. Run Application and you will see it initially in the center of the screen at a larger non-DPI aware size and then move of center when it is corrected to the DPI aware size

Attached Sample: [SplashScreenProblem.zip](https://github.com/dotnet/wpf/files/6982221/SplashScreenProblem.zip)