Python: Bug fix for azure ai agent truncate strategy. Add sample. (#11503)

### Motivation and Context

We are not handling the AzureAIAgent truncation strategy object
correctly in AgentThreadActions. Fix this and add a sample showing how
to configure the object during agent invocation.

<!-- Thank you for your contribution to the semantic-kernel repo!
Please help reviewers and future users, providing the following
information:
  1. Why is this change required?
  2. What problem does it solve?
  3. What scenario does it contribute to?
  4. If it fixes an open issue, please link to the issue here.
-->

### Description

Bug fix and sample.

<!-- Describe your changes, the overall approach, the underlying design.
These notes will help understanding how your code works. Thanks! -->

### Contribution Checklist

<!-- Before submitting this PR, please make sure: -->

- [X] The code builds clean without any errors or warnings
- [X] The PR follows the [SK Contribution
Guidelines](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
and the [pre-submission formatting
script](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [X] All unit tests pass, and I have added new tests where possible
- [X] I didn't break anyone 😄

Author: moonbox3

python/samples/concepts/README.md

@@ -16,6 +16,7 @@
 - [Azure AI Agent Message Callback](./agents/azure_ai_agent/azure_ai_agent_message_callback.py)
 - [Azure AI Agent Streaming](./agents/azure_ai_agent/azure_ai_agent_streaming.py)
 - [Azure AI Agent Structured Outputs](./agents/azure_ai_agent/azure_ai_agent_structured_outputs.py)
+- [Azure AI Agent Truncation Strategy](./agents/azure_ai_agent/azure_ai_agent_truncation_strategy.py)
 
 #### [Bedrock Agent](../../semantic_kernel/agents/bedrock/bedrock_agent.py)
 

python/samples/concepts/agents/azure_ai_agent/azure_ai_agent_truncation_strategy.py

@@ -0,0 +1,85 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+import asyncio
+
+from azure.ai.projects.models import TruncationObject
+from azure.identity.aio import DefaultAzureCredential
+
+from semantic_kernel.agents import (
+    AzureAIAgent,
+    AzureAIAgentSettings,
+    AzureAIAgentThread,
+)
+
+"""
+The following sample demonstrates how to create an Azure AI Agent Agent
+and configure a truncation strategy for the agent.
+"""
+
+USER_INPUTS = [
+    "Why is the sky blue?",
+    "What is the speed of light?",
+    "What have we been talking about?",
+]
+
+
+async def main() -> None:
+    ai_agent_settings = AzureAIAgentSettings.create()
+
+    async with (
+        DefaultAzureCredential() as creds,
+        AzureAIAgent.create_client(
+            credential=creds,
+            conn_str=ai_agent_settings.project_connection_string.get_secret_value(),
+        ) as client,
+    ):
+        # Create the agent definition
+        agent_definition = await client.agents.create_agent(
+            model=ai_agent_settings.model_deployment_name,
+            name="TruncateAgent",
+            instructions="You are a helpful assistant that answers user questions in one sentence.",
+        )
+
+        # Create the AzureAI Agent
+        agent = AzureAIAgent(
+            client=client,
+            definition=agent_definition,
+        )
+
+        thread: AzureAIAgentThread | None = None
+
+        # Options are "auto" or "last_messages"
+        # If using "last_messages", specify the number of messages to keep with `last_messages` kwarg
+        truncation_strategy = TruncationObject(type="last_messages", last_messages=2)
+
+        try:
+            for user_input in USER_INPUTS:
+                print(f"# User: {user_input}")
+                # 4. Invoke the agent with the specified message for response
+                response = await agent.get_response(
+                    messages=user_input, thread=thread, truncation_strategy=truncation_strategy
+                )
+                print(f"# {response.name}: {response}")
+                thread = response.thread
+        finally:
+            # 6. Cleanup: Delete the thread and agent
+            await thread.delete() if thread else None
+            await client.agents.delete_agent(agent.id)
+
+    """
+    Sample Output:
+
+    # User: Why is the sky blue?
+    # TruncateAgent: The sky appears blue because molecules in the Earth's atmosphere scatter sunlight in all 
+        directions, and blue light is scattered more than other colors due to its shorter wavelength.
+    # User: What is the speed of light?
+    # TruncateAgent: The speed of light in a vacuum is approximately 299,792,458 meters per second 
+        (or about 186,282 miles per second).
+    # User: What have we been talking about?
+    # TruncateAgent: I'm sorry, but I don't have access to previous interactions. Could you remind me what 
+        we've been discussing?
+    """
+
+
+if __name__ == "__main__":
+    asyncio.run(main())

python/semantic_kernel/agents/azure_ai/agent_thread_actions.py

@@ -725,7 +725,7 @@ def _merge_options(
     def _generate_options(cls: type[_T], **kwargs: Any) -> dict[str, Any]:
         """Generate a dictionary of options that can be passed directly to create_run."""
         merged = cls._merge_options(**kwargs)
-        trunc_count = merged.get("truncation_message_count", None)
+        truncation_strategy = merged.get("truncation_strategy", None)
         max_completion_tokens = merged.get("max_completion_tokens", None)
         max_prompt_tokens = merged.get("max_prompt_tokens", None)
         parallel_tool_calls = merged.get("parallel_tool_calls_enabled", None)
@@ -735,7 +735,7 @@ def _generate_options(cls: type[_T], **kwargs: Any) -> dict[str, Any]:
             "top_p": merged.get("top_p"),
             "response_format": merged.get("response_format"),
             "temperature": merged.get("temperature"),
-            "truncation_strategy": trunc_count,
+            "truncation_strategy": truncation_strategy,
             "metadata": merged.get("metadata"),
             "max_completion_tokens": max_completion_tokens,
             "max_prompt_tokens": max_prompt_tokens,