chore: Update live multi agent sample with latest live models

Co-authored-by: Xiang (Sean) Zhou <[email protected]>
PiperOrigin-RevId: 853769664

Author: seanzhougoogle

contributing/samples/live_bidi_streaming_multi_agent/agent.py

@@ -30,8 +30,11 @@ def roll_die(sides: int) -> int:
 roll_agent = Agent(
     name="roll_agent",
     model=Gemini(
-        # model="gemini-2.0-flash-live-preview-04-09",  # for Vertex project
-        model="gemini-live-2.5-flash-preview",  # for AI studio key
+        # see https://docs.cloud.google.com/vertex-ai/generative-ai/docs/migrate
+        # for vertex model names
+        model="gemini-live-2.5-flash-native-audio",  # vertex
+        # see https://ai.google.dev/gemini-api/docs/models for AIS model names
+        # model='gemini-2.5-flash-native-audio-latest',  # for AI studio
         speech_config=types.SpeechConfig(
             voice_config=types.VoiceConfig(
                 prebuilt_voice_config=types.PrebuiltVoiceConfig(
@@ -82,8 +85,11 @@ def check_prime(nums: list[int]) -> str:
 prime_agent = Agent(
     name="prime_agent",
     model=Gemini(
-        # model="gemini-2.0-flash-live-preview-04-09",  # for Vertex project
-        model="gemini-live-2.5-flash-preview",  # for AI studio key
+        # see https://docs.cloud.google.com/vertex-ai/generative-ai/docs/migrate
+        # for vertex model names
+        model="gemini-live-2.5-flash-native-audio",  # vertex
+        # see https://ai.google.dev/gemini-api/docs/models for AIS model names
+        # model='gemini-2.5-flash-native-audio-latest',  # for AI studio
         speech_config=types.SpeechConfig(
             voice_config=types.VoiceConfig(
                 prebuilt_voice_config=types.PrebuiltVoiceConfig(
@@ -124,8 +130,11 @@ def get_current_weather(location: str):
 root_agent = Agent(
     # find supported models here: https://google.github.io/adk-docs/get-started/streaming/quickstart-streaming/
     model=Gemini(
-        # model="gemini-2.0-flash-live-preview-04-09",  # for Vertex project
-        model="gemini-live-2.5-flash-preview",  # for AI studio key
+        # see https://docs.cloud.google.com/vertex-ai/generative-ai/docs/migrate
+        # for vertex model names
+        model="gemini-live-2.5-flash-native-audio",  # vertex
+        # see https://ai.google.dev/gemini-api/docs/models for AIS model names
+        # model='gemini-2.5-flash-native-audio-latest',  # for AI studio
         speech_config=types.SpeechConfig(
             voice_config=types.VoiceConfig(
                 prebuilt_voice_config=types.PrebuiltVoiceConfig(