Switch remaining tests from Pigeon generated tests to mockito

packages/video_player/video_player_android/lib/src/android_video_player.dart

@@ -21,11 +21,13 @@ VideoPlayerInstanceApi _productionApiProvider(int mapId) {
 class AndroidVideoPlayer extends VideoPlayerPlatform {
   /// Creates a new Android maps implementation instance.
   AndroidVideoPlayer({
+    @visibleForTesting AndroidVideoPlayerApi? pluginApi,
     @visibleForTesting
     VideoPlayerInstanceApi Function(int playerId)? apiProvider,
-  }) : _apiProvider = apiProvider ?? _productionApiProvider;
+  }) : _api = pluginApi ?? AndroidVideoPlayerApi(),
+       _apiProvider = apiProvider ?? _productionApiProvider;
 
-  final AndroidVideoPlayerApi _api = AndroidVideoPlayerApi();
+  final AndroidVideoPlayerApi _api;
   // A method to create VideoPlayerInstanceApi instances, which can be
   //overridden for testing.
   final VideoPlayerInstanceApi Function(int mapId) _apiProvider;

packages/video_player/video_player_android/pigeons/messages.dart

@@ -7,7 +7,6 @@ import 'package:pigeon/pigeon.dart';
 @ConfigurePigeon(
   PigeonOptions(
     dartOut: 'lib/src/messages.g.dart',
-    dartTestOut: 'test/test_api.g.dart',
     javaOut:
         'android/src/main/java/io/flutter/plugins/videoplayer/Messages.java',
     javaOptions: JavaOptions(package: 'io.flutter.plugins.videoplayer'),
@@ -34,7 +33,7 @@ class CreateMessage {
   PlatformVideoViewType? viewType;
 }
 
-@HostApi(dartHostTestHandler: 'TestHostVideoPlayerApi')
+@HostApi()
 abstract class AndroidVideoPlayerApi {
   void initialize();
   int create(CreateMessage msg);