Take screenshots by always passing afterScreenUpdates:YES.

Motivation: a lot of tests use `[GREYScreenshotter snapshotElement]` method to take screenshots which currently uses `afterScreenUpdates:NO`. This means that changes done in the current run loop iteration won't be visible in the screenshot. This can cause flakiness and it's better to always use `afterScreenUpdates:YES` to get the most accurate current UI state.
PiperOrigin-RevId: 570316525

UILib/GREYScreenshotter.m

@@ -94,10 +94,12 @@ + (UIImage *)snapshotElement:(id)element {
   UIScreen *mainScreen = MainScreen();
   if (!mainScreen) return nil;
   UIGraphicsBeginImageContextWithOptions(elementAXFrame.size, NO, mainScreen.scale);
+  // We want to capture the most up-to-date version of the screen here, including the updates that
+  // have been made in the current runloop iteration. Therefore we use `afterScreenUpdates:YES`.
   [self drawViewInContext:UIGraphicsGetCurrentContext()
                      view:viewToSnapshot
                    bounds:elementAXFrame
-       afterScreenUpdates:NO];
+       afterScreenUpdates:YES];
   UIImage *orientedScreenshot = UIGraphicsGetImageFromCurrentImageContext();
   UIGraphicsEndImageContext();