fix(firebaseai): remove candidateCount from LiveGenerationConfig since the connection fails silently when it is set (#17647)

Author: cynthiajoan

packages/firebase_ai/firebase_ai/lib/src/live_api.dart

@@ -77,7 +77,6 @@ final class LiveGenerationConfig extends BaseGenerationConfig {
   LiveGenerationConfig({
     this.speechConfig,
     super.responseModalities,
-    super.candidateCount,
     super.maxOutputTokens,
     super.temperature,
     super.topP,

packages/firebase_ai/firebase_ai/test/live_test.dart

@@ -43,15 +43,13 @@ void main() {
       final liveGenerationConfig = LiveGenerationConfig(
         speechConfig: SpeechConfig(voiceName: 'Charon'),
         responseModalities: [ResponseModalities.text, ResponseModalities.audio],
-        candidateCount: 2,
         maxOutputTokens: 100,
         temperature: 0.8,
         topP: 0.95,
         topK: 40,
       );
 
       expect(liveGenerationConfig.toJson(), {
-        'candidateCount': 2,
         'maxOutputTokens': 100,
         'temperature': 0.8,
         'topP': 0.95,

packages/firebase_vertexai/firebase_vertexai/test/live_test.dart

@@ -44,15 +44,13 @@ void main() {
       final liveGenerationConfig = LiveGenerationConfig(
         speechConfig: SpeechConfig(voiceName: 'Charon'),
         responseModalities: [ResponseModalities.text, ResponseModalities.audio],
-        candidateCount: 2,
         maxOutputTokens: 100,
         temperature: 0.8,
         topP: 0.95,
         topK: 40,
       );
 
       expect(liveGenerationConfig.toJson(), {
-        'candidateCount': 2,
         'maxOutputTokens': 100,
         'temperature': 0.8,
         'topP': 0.95,