Make sure that a GridTileBar doesn't crash in 0x0 environment (flutter#177546)

This is my attempt to handle
flutter#6537 for the GridTileBar
widget.

Co-authored-by: Tong Mu <dkwingsmt@users.noreply.github.com>

Author: ahmedsameha1

packages/flutter/test/material/grid_title_test.dart

@@ -47,4 +47,15 @@ void main() {
 
     expect(find.text('Simple'), findsOneWidget);
   });
+
+  testWidgets('GridTileBar does not crash at zero area', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      const MaterialApp(
+        home: Center(
+          child: SizedBox.shrink(child: GridTileBar(title: Text('X'))),
+        ),
+      ),
+    );
+    expect(tester.getSize(find.byType(GridTileBar)), Size.zero);
+  });
 }