Fix issue with bold not being applied

Author: marcelwgn

Microsoft.Toolkit.Uwp.SampleApp/SamplePages/StringExtensions/StringExtensionsPage.xaml.cs

@@ -35,10 +35,10 @@ private void ValidateCurrentText()
             IsValidDecimalResult.FontWeight = InputTextBox.Text.IsDecimal() ? FontWeights.Bold : FontWeights.Normal;
 
             IsValidStringResult.Text = InputTextBox.Text.IsCharacterString().ToString();
-            IsValidPhoneNumberResult.FontWeight = InputTextBox.Text.IsCharacterString() ? FontWeights.Bold : FontWeights.Normal;
+            IsValidStringResult.FontWeight = InputTextBox.Text.IsCharacterString() ? FontWeights.Bold : FontWeights.Normal;
 
             IsValidPhoneNumberResult.Text = InputTextBox.Text.IsPhoneNumber().ToString();
             IsValidPhoneNumberResult.FontWeight = InputTextBox.Text.IsPhoneNumber() ? FontWeights.Bold : FontWeights.Normal;
         }
     }
-}
+}