Update GeminiMultimodalLiveLLMService to use Gemini 2.5 Flash Native Audio Dialog model

CHANGELOG.md

@@ -79,6 +79,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Updated the default model for `AnthropicLLMService` to
   `claude-sonnet-4-20250514`.
 
+- Updated the default model for `GeminiMultimodalLiveLLMService` to
+  `models/gemini-2.5-flash-preview-native-audio-dialog`.
+
 - `BaseTextFilter` methods `filter()`, `update_settings()`,
   `handle_interruption()` and `reset_interruption()` are now async.
 

src/pipecat/services/gemini_multimodal_live/gemini.py

@@ -335,7 +335,7 @@ class GeminiMultimodalLiveLLMService(LLMService):
         *,
         api_key: str,
         base_url: str = "generativelanguage.googleapis.com/ws/google.ai.generativelanguage.v1beta.GenerativeService.BidiGenerateContent",
-        model="models/gemini-2.0-flash-live-001",
+        model="models/gemini-2.5-flash-preview-native-audio-dialog",
         voice_id: str = "Charon",
         start_audio_paused: bool = False,
         start_video_paused: bool = False,