chore: model upgrade in samples (#423)

Author: vishwarajanand

samples/langchain_on_vertexai/prebuilt_langchain_agent_template.py

@@ -76,7 +76,7 @@ def similarity_search(query: str) -> list[Document]:
 # Uncomment to test locally
 
 # app = reasoning_engines.LangchainAgent(
-#     model="gemini-pro",
+#     model="gemini-2.0-flash-001",
 #     tools=[similarity_search],
 #     model_kwargs={
 #         "temperature": 0.1,
@@ -93,7 +93,7 @@ def similarity_search(query: str) -> list[Document]:
 
 remote_app = reasoning_engines.ReasoningEngine.create(
     reasoning_engines.LangchainAgent(
-        model="gemini-pro",
+        model="gemini-2.0-flash-001",
         tools=[similarity_search],
         model_kwargs={
             "temperature": 0.1,

samples/langchain_on_vertexai/retriever_agent_with_history_template.py

@@ -154,7 +154,7 @@ def query(self, input: str, session_id: str) -> str:
 
 # Uncomment to test locally
 # app = AlloyDBAgent(
-#     model="gemini-pro",
+#     model="gemini-2.0-flash-001",
 #     project=PROJECT_ID,
 #     region=REGION,
 #     cluster=CLUSTER,
@@ -177,7 +177,7 @@ def query(self, input: str, session_id: str) -> str:
 
 remote_app = reasoning_engines.ReasoningEngine.create(
     AlloyDBAgent(
-        model="gemini-pro",
+        model="gemini-2.0-flash-001",
         project=PROJECT_ID,
         region=REGION,
         cluster=CLUSTER,

samples/langchain_on_vertexai/retriever_chain_template.py

@@ -126,7 +126,7 @@ def query(self, input: str) -> str:
 # Uncomment to test locally
 
 # app = AlloyDBRetriever(
-#     model="gemini-pro",
+#     model="gemini-2.0-flash-001",
 #     project=PROJECT_ID,
 #     region=REGION,
 #     cluster=CLUSTER,
@@ -147,7 +147,7 @@ def query(self, input: str) -> str:
 
 remote_app = reasoning_engines.ReasoningEngine.create(
     AlloyDBRetriever(
-        model="gemini-pro",
+        model="gemini-2.0-flash-001",
         project=PROJECT_ID,
         region=REGION,
         cluster=CLUSTER,