Fix placeholder text truncation for OneWay and TwoWay Binding

[sabareesanms]

Bug: [WinUI 3 Gallery: Fundamentals -> Binding]: On applying text scaling 200%, the placeholder text of OneWay Binding and TwoWay Binding are getting truncated.

Description:
The placeholder text of the textbox in the binding page is getting truncated when the text scaling is set to 200%.

Changes:
Files changed
WinUIGallery/Samples/ControlPages/Fundamentals/BindingPage.xaml

Code changes:
Width="200" is changed to MinWidth="380"

 <TextBox
     x:Name="SourceTextBoxOneWay"
     MinWidth="380"
     HorizontalAlignment="Left"
     PlaceholderText="Enter text here" />

Test:
Tested in the gallery app. Attached the screenshots for reference.

Screenshots:

Normal State:

Text Scaling Set to 200%:

Before fix:

After fix:

[sabareesanms]

/azp run