[google_maps_flutter] Support for Ground Overlay (flutter#8432)

Adds Ground Overlay support for google_maps_flutter plugin.

Fixes flutter#26479

[Android](https://developers.google.com/maps/documentation/android-sdk/groundoverlay):
<img src="https://github.com/user-attachments/assets/1b1b4b9b-0260-49c4-87ed-4de29f4741db" width=40%>

[iOS](https://developers.google.com/maps/documentation/ios-sdk/overlays):
<img src="https://github.com/user-attachments/assets/fd24e73d-70a0-4972-b7c2-595acc79c2e9" width=40%>

[Web](https://developers.google.com/maps/documentation/javascript/groundoverlays):
<img src="https://github.com/user-attachments/assets/06015fa8-6cc4-46ad-81f1-95966015d338" width=60%>

Documentation for groundOverlays parameter on app-facing plugin:
<img width="736" alt="documentation" src="https://github.com/user-attachments/assets/81bef3cb-2167-44fc-9c44-b45399ed4d30" />

Author: jokerttu

packages/google_maps_flutter/google_maps_flutter/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 2.11.0
+
+* Adds support for ground overlays.
+* Updates minimum supported SDK version to Flutter 3.27/Dart 3.6.
+
 ## 2.10.1
 
 * Updates READMEs and API docs.