[google_maps_flutter] Add a new zIndexInt param to marker and deprecate zIndex (#8012)

*Replace this paragraph with a description of what this PR is changing or adding, and why. Consider including before/after screenshots.*
`zIndex` on marker is currently a double. This introduces inconsistency between its behaviours on android and ios since ios truncates it to an int. This PR aims to smooth out that difference by accepting an int param instead through the marker API in dart

*List which issues are fixed by this PR. You must list at least one issue.*
Fixes flutter/flutter#155897

Author: Hari-07

packages/google_maps_flutter/google_maps_flutter/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.12.3
+
+* Updates the example app to use the zIndexInt param instead of the deprecated zIndex.
+
 ## 2.12.2
 
 * Fixes memory leak by disposing stream subscriptions in `GoogleMapController`.

packages/google_maps_flutter/google_maps_flutter/example/integration_test/src/maps_inspector.dart

@@ -889,7 +889,7 @@ Marker _copyMarkerWithClusterManagerId(
     position: marker.position,
     rotation: marker.rotation,
     visible: marker.visible,
-    zIndex: marker.zIndex,
+    zIndexInt: marker.zIndexInt,
     onTap: marker.onTap,
     onDragStart: marker.onDragStart,
     onDrag: marker.onDrag,

packages/google_maps_flutter/google_maps_flutter/example/lib/place_marker.dart

@@ -249,10 +249,10 @@ class PlaceMarkerBodyState extends State<PlaceMarkerBody> {
 
   Future<void> _changeZIndex(MarkerId markerId) async {
     final Marker marker = markers[markerId]!;
-    final double current = marker.zIndex;
+    final int current = marker.zIndexInt;
     setState(() {
       markers[markerId] = marker.copyWith(
-        zIndexParam: current == 12.0 ? 0.0 : current + 1.0,
+        zIndexIntParam: current == 12 ? 0 : current + 1,
       );
     });
   }

packages/google_maps_flutter/google_maps_flutter/example/pubspec.yaml

@@ -18,8 +18,8 @@ dependencies:
     # The example app is bundled with the plugin so we use a path dependency on
     # the parent directory to use the current plugin's version.
     path: ../
-  google_maps_flutter_android: ^2.16.0
-  google_maps_flutter_platform_interface: ^2.11.0
+  google_maps_flutter_android: ^2.16.1
+  google_maps_flutter_platform_interface: ^2.12.1
 
 dev_dependencies:
   build_runner: ^2.1.10

packages/google_maps_flutter/google_maps_flutter/pubspec.yaml

@@ -2,7 +2,7 @@ name: google_maps_flutter
 description: A Flutter plugin for integrating Google Maps in iOS and Android applications.
 repository: https://github.com/flutter/packages/tree/main/packages/google_maps_flutter/google_maps_flutter
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+maps%22
-version: 2.12.2
+version: 2.12.3
 
 environment:
   sdk: ^3.6.0
@@ -21,9 +21,9 @@ flutter:
 dependencies:
   flutter:
     sdk: flutter
-  google_maps_flutter_android: ^2.16.0
-  google_maps_flutter_ios: ^2.15.0
-  google_maps_flutter_platform_interface: ^2.11.0
+  google_maps_flutter_android: ^2.16.1
+  google_maps_flutter_ios: ^2.15.4
+  google_maps_flutter_platform_interface: ^2.12.1
   google_maps_flutter_web: ^0.5.12
 
 dev_dependencies: