[Android] Session serialization uses base type instead of child for ConversationFunctionTool

[maratoss]

Service

OpenAI

Describe the bug

Hi! Could you help me with the problem.

Smth wrong with serialization:
It sends request with wrong session's json
instead of using ConversationFunctionTool it uses base class ConversationTool
the session:

the serialized session:

{
	"session": {
		"instructions": "*hidden*",
		"voice": "alloy",
		"input_audio_format": "pcm16",
		"output_audio_format": "pcm16",
		"input_audio_transcription": {
			"model": "whisper-1"
		},
		"tools": [
			{
				"type": "function"
			},
			{
				"type": "function"
			},
			{
				"type": "function"
			},
			{
				"type": "function"
			},
			{
				"type": "function"
			},
			{
				"type": "function"
			},
			{
				"type": "function"
			},
			{
				"type": "function"
			},
			{
				"type": "function"
			},
			{
				"type": "function"
			},
			{
				"type": "function"
			}
		],
		"tool_choice": "auto"
	},
	"type": "session.update"
}

the following changes in ConversationSessionOptions.Serialization.cs fix the problem:

Steps to reproduce

1. Need to create maui android project
2. Create a session with Tools and Functions
3. Configure the session
4. it should send a corrected json

Code snippets

No response

OS

Android

.NET version

net8.0-android

Library version

2.1.0-beta.2