Update for Flutter 3.10 beta (#1746)

## Pre-launch Checklist

- [x] I read the [Flutter Style Guide] _recently_, and have followed its
advice.
- [x] I signed the [CLA].
- [x] I read the [Contributors Guide].
- [x] I updated/added relevant documentation (doc comments with `///`).
- [ ] All existing and new tests are passing.

---------

Co-authored-by: David Iglesias <ditman@gmail.com>
Co-authored-by: Mark Thompson <2554588+MarkTechson@users.noreply.github.com>
Co-authored-by: John Ryan <ryjohn@google.com>

place_tracker/lib/place_tracker_app.dart

@@ -67,9 +67,9 @@ class _PlaceTrackerHomePage extends StatelessWidget {
     var state = Provider.of<AppState>(context);
     return Scaffold(
       appBar: AppBar(
-        title: Row(
+        title: const Row(
           crossAxisAlignment: CrossAxisAlignment.center,
-          children: const [
+          children: [
             Padding(
               padding: EdgeInsets.fromLTRB(0.0, 0.0, 8.0, 0.0),
               child: Icon(Icons.pin_drop, size: 24.0),