add page delays to the fullscreen versions of the textfield perf benchmarks (#107746)

dev/benchmarks/macrobenchmarks/test/fullscreen_textfield_perf_e2e.dart

@@ -12,11 +12,7 @@ void main() {
   macroPerfTestE2E(
     'fullscreen_textfield_perf',
     kFullscreenTextRouteName,
-    // The driver version doesn't have this delay because the delay caused
-    // by the communication between the host and the test device is long enough
-    // for the driver test, but there isn't such delay in this host independent
-    // test.
-    pageDelay: const Duration(milliseconds: 50),
+    pageDelay: const Duration(seconds: 1),
     body: (WidgetController controller) async {
       final Finder textfield = find.byKey(const ValueKey<String>('fullscreen-textfield'));
       controller.tap(textfield);

dev/benchmarks/macrobenchmarks/test_driver/fullscreen_textfield_perf_test.dart

@@ -11,7 +11,7 @@ void main() {
   macroPerfTest(
     'fullscreen_textfield_perf',
     kFullscreenTextRouteName,
-    pageDelay: const Duration(milliseconds: 50),
+    pageDelay: const Duration(seconds: 1),
     driverOps: (FlutterDriver driver) async {
       final SerializableFinder textfield = find.byValueKey('fullscreen-textfield');
       driver.tap(textfield);