Revert "[Android] picker - focus/unfocus events (#28122)"

This reverts commit dfeadeb.

Author: PureWeen

src/Controls/tests/TestCases.HostApp/Issues/Issue28121.xaml

@@ -152,14 +152,10 @@ void OnClick(object? sender, EventArgs e)
 
 				_dialog.SetCanceledOnTouchOutside(true);
 
-				_dialog.DismissEvent += OnDismiss;
-
-				void OnDismiss(object? s, EventArgs e)
+				_dialog.DismissEvent += (sender, args) =>
 				{
-					_dialog.DismissEvent -= OnDismiss;
-					PlatformView?.ClearFocus();
 					_dialog = null;
-				}
+				};
 
 				_dialog.Show();
 			}