#164680 is solving a similar issue.

Reiterating from the other PR: we do want to change the SystemUiOverlayStyle on both platforms. It causes the overlay to be visible when it goes from having a light background to a dark background mid transition. So if we remove it, it looks like this:

When we want this:

The problem is that when a sheet route is pushed, it wraps the previous route with it's delegatedTransition, which has the set SystemUiOverlayStyle. When the sheet is removed with a drag, the delegatedTransition sticks around so the overlay style wasn't being reset. The other PR fixes this by not setting it depending on the animation status.

For Android specifically, we probably don't need to ever set the bottom system UI. That could be fixed by changing the way the overlay style is set from

SystemChrome.setSystemUIOverlayStyle(SystemUiOverlayStyle.light);

to

SystemChrome.setSystemUIOverlayStyle(
  const SystemUiOverlayStyle(
    statusBarBrightness: Brightness.dark,
    statusBarIconBrightness: Brightness.light,
  ),
);