[Testing] Fixed Build error on inflight/ candidate PR 35716 (#35730)

This pull request makes layout adjustments to the `Issue7814` test case
to improve clarity and maintainability. The main changes involve
explicitly setting the grid positions of UI elements instead of using
extension methods, which helps make the layout logic more transparent.

**Layout adjustments:**

* Explicitly set the column for `_horizontalOffsetLabel` using
`Grid.SetColumn` instead of the `.Column(1)` extension method.
[[1]](diffhunk://#diff-a564b2a91bf588cf9e13398f6e1dcfac2f9345c027b39d5accbc02f9792360daR17-R26)
[[2]](diffhunk://#diff-a564b2a91bf588cf9e13398f6e1dcfac2f9345c027b39d5accbc02f9792360daL45-R51)
* Explicitly set the row for `outerScrollView` using `Grid.SetRow`
instead of the `.Row(1)` extension method.
[[1]](diffhunk://#diff-a564b2a91bf588cf9e13398f6e1dcfac2f9345c027b39d5accbc02f9792360daR17-R26)
[[2]](diffhunk://#diff-a564b2a91bf588cf9e13398f6e1dcfac2f9345c027b39d5accbc02f9792360daL45-R51)

Author: HarishKumarSF4517

src/Controls/tests/TestCases.HostApp/Issues/Issue7814.cs

@@ -14,13 +14,16 @@ protected override void Init()
 		_verticalOffsetLabel = CreateOffsetLabel("Issue7814VerticalScrollYLabel", VerticalOffsetPrefix);
 		_horizontalOffsetLabel = CreateOffsetLabel("Issue7814HorizontalScrollXLabel", HorizontalOffsetPrefix);
 
+		Grid.SetColumn(_horizontalOffsetLabel, 1);
+
 		var outerScrollView = new ScrollView
 		{
 			AutomationId = "Issue7814OuterScrollView",
 			Orientation = ScrollOrientation.Vertical,
 			Content = CreateScrollableContent()
 		};
 		outerScrollView.Scrolled += (_, e) => UpdateOffset(_verticalOffsetLabel, VerticalOffsetPrefix, e.ScrollY);
+		Grid.SetRow(outerScrollView, 1);
 
 		Content = new Grid
 		{
@@ -42,10 +45,10 @@ protected override void Init()
 					Children =
 					{
 						_verticalOffsetLabel,
-						_horizontalOffsetLabel.Column(1)
+						_horizontalOffsetLabel
 					}
 				},
-				outerScrollView.Row(1)
+				outerScrollView
 			}
 		};
 	}