fix(vertexai): add missing HarmBlockThreshold to exported APIs (#17249)

* added HarmBlockMethod to firebase_vertexai

* added Dinu-Stefan Rusu in authors list

* removed unused api import for chat_test and model_test in vertexai package

Author: rusudinu

AUTHORS

@@ -65,3 +65,4 @@ Om Phatak <everythingoutdated@gmail.com>
 Horváth István <horvatska01@gmail.com>
 Liu Zhisong <liuzs0666@gmail.com>
 Ievgenii Kovtun <jeka.ns@gmail.com>
+Dinu-Stefan Rusu <rusudinustefan@gmail.com>

packages/firebase_vertexai/firebase_vertexai/lib/firebase_vertexai.dart

@@ -25,6 +25,7 @@ export 'src/api.dart'
         HarmBlockThreshold,
         HarmCategory,
         HarmProbability,
+        HarmBlockMethod,
         PromptFeedback,
         SafetyRating,
         SafetySetting,

packages/firebase_vertexai/firebase_vertexai/test/chat_test.dart

@@ -13,7 +13,6 @@
 // limitations under the License.
 import 'package:firebase_core/firebase_core.dart';
 import 'package:firebase_vertexai/firebase_vertexai.dart';
-import 'package:firebase_vertexai/src/api.dart';
 import 'package:firebase_vertexai/src/base_model.dart';
 import 'package:flutter_test/flutter_test.dart';
 

packages/firebase_vertexai/firebase_vertexai/test/model_test.dart

@@ -13,7 +13,6 @@
 // limitations under the License.
 import 'package:firebase_core/firebase_core.dart';
 import 'package:firebase_vertexai/firebase_vertexai.dart';
-import 'package:firebase_vertexai/src/api.dart';
 import 'package:firebase_vertexai/src/base_model.dart';
 import 'package:flutter_test/flutter_test.dart';