[google_maps_flutter] Clean Java test, consolidate Marker example. (#4400)

* Do not mock internal class
* Merge "Marker" examples into a single page.

Author: JamesMcIntosh

packages/google_maps_flutter/google_maps_flutter/android/src/test/java/io/flutter/plugins/googlemaps/MarkersControllerTest.java

@@ -9,7 +9,6 @@
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.when;
 
-import com.google.android.gms.internal.maps.zzt;
 import com.google.android.gms.maps.GoogleMap;
 import com.google.android.gms.maps.model.LatLng;
 import com.google.android.gms.maps.model.Marker;
@@ -35,8 +34,7 @@ public void controller_OnMarkerDragStart() {
     final GoogleMap googleMap = mock(GoogleMap.class);
     controller.setGoogleMap(googleMap);
 
-    final zzt z = mock(zzt.class);
-    final Marker marker = new Marker(z);
+    final Marker marker = mock(Marker.class);
 
     final String googleMarkerId = "abc123";
 
@@ -69,8 +67,7 @@ public void controller_OnMarkerDragEnd() {
     final GoogleMap googleMap = mock(GoogleMap.class);
     controller.setGoogleMap(googleMap);
 
-    final zzt z = mock(zzt.class);
-    final Marker marker = new Marker(z);
+    final Marker marker = mock(Marker.class);
 
     final String googleMarkerId = "abc123";
 
@@ -103,8 +100,7 @@ public void controller_OnMarkerDrag() {
     final GoogleMap googleMap = mock(GoogleMap.class);
     controller.setGoogleMap(googleMap);
 
-    final zzt z = mock(zzt.class);
-    final Marker marker = new Marker(z);
+    final Marker marker = mock(Marker.class);
 
     final String googleMarkerId = "abc123";
 

packages/google_maps_flutter/google_maps_flutter/example/lib/drag_marker.dart

@@ -5,7 +5,6 @@
 // ignore_for_file: public_member_api_docs
 
 import 'package:flutter/material.dart';
-import 'package:google_maps_flutter_example/drag_marker.dart';
 import 'package:google_maps_flutter_example/lite_mode.dart';
 import 'animate_camera.dart';
 import 'map_click.dart';
@@ -35,7 +34,6 @@ final List<GoogleMapExampleAppPage> _allPages = <GoogleMapExampleAppPage>[
   PlacePolylinePage(),
   PlacePolygonPage(),
   PlaceCirclePage(),
-  DragMarkerPage(),
   PaddingPage(),
   SnapshotPage(),
   LiteModePage(),