Update firebase-ai/src/main/kotlin/com/google/firebase/ai/type/ConversationConfig.kt

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: VinayGuthal

firebase-ai/src/main/kotlin/com/google/firebase/ai/type/ConversationConfig.kt

@@ -44,10 +44,10 @@ import android.media.AudioTrack
 @PublicPreviewAPI
 public class ConversationConfig
 private constructor(
-  internal var functionCallHandler: ((FunctionCallPart) -> FunctionResponsePart)?,
-  internal var audioHandler: ((AudioRecord, AudioTrack) -> Unit)?,
-  internal var transcriptHandler: ((Transcription?, Transcription?) -> Unit)?,
-  internal var enableInterruptions: Boolean
+  internal val functionCallHandler: ((FunctionCallPart) -> FunctionResponsePart)?,
+  internal val audioHandler: ((AudioRecord, AudioTrack) -> Unit)?,
+  internal val transcriptHandler: ((Transcription?, Transcription?) -> Unit)?,
+  internal val enableInterruptions: Boolean
 ) {
 
   /**