Sync Snippet from example to README

Author: DEVSOG12

packages/google_maps_flutter/google_maps_flutter/README.md

@@ -109,7 +109,50 @@ the `GoogleMap`'s `onMapCreated` callback.
 
 <?code-excerpt "readme_sample.dart (MapSample)"?>
 ```dart
+class MapSample extends StatefulWidget {
+  const MapSample({Key? key}) : super(key: key);
 
+  @override
+  State<MapSample> createState() => MapSampleState();
+}
+
+class MapSampleState extends State<MapSample> {
+  final Completer<GoogleMapController> _controller =
+      Completer<GoogleMapController>();
+
+  static const CameraPosition _kGooglePlex = CameraPosition(
+    target: LatLng(37.42796133580664, -122.085749655962),
+    zoom: 14.4746,
+  );
+
+  static const CameraPosition _kLake = CameraPosition(
+      bearing: 192.8334901395799,
+      target: LatLng(37.43296265331129, -122.08832357078792),
+      tilt: 59.440717697143555,
+      zoom: 19.151926040649414);
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: GoogleMap(
+        mapType: MapType.hybrid,
+        initialCameraPosition: _kGooglePlex,
+        onMapCreated: (GoogleMapController controller) {
+          _controller.complete(controller);
+        },
+      ),
+      floatingActionButton: FloatingActionButton.extended(
+        onPressed: _goToTheLake,
+        label: const Text('To the lake!'),
+        icon: const Icon(Icons.directions_boat),
+      ),
+    );
+  }
+
+  Future<void> _goToTheLake() async {
+    final GoogleMapController controller = await _controller.future;
+    controller.animateCamera(CameraUpdate.newCameraPosition(_kLake));
+  }
 ```
 
 See the `example` directory for a complete sample app.