Add a new response api

packages/firebase_vertexai/firebase_vertexai/lib/src/live_api.dart

@@ -176,6 +176,49 @@ class LiveServerToolCallCancellation implements LiveServerMessage {
   final List<String>? functionIds;
 }
 
+/// The status of a live generation response.
+enum LiveResponseStatus {
+  /// The live generation is proceeding normally, and more content might be streamed.
+  normal,
+
+  /// A client message has interrupted current model generation. If the client
+  /// is playing out the content in realtime, this is a good signal to stop and
+  /// empty the current queue.
+  interrupted,
+
+  /// The model is done generating. Generation will only start in response to
+  /// additional client messages.
+  turnComplete,
+}
+
+/// A single response chunk received during a live content generation.
+///
+/// It can contain generated content, function calls to be executed, or
+/// instructions to cancel previous function calls, along with the status of the
+/// ongoing generation.
+class LiveContentResponse {
+  // ignore: public_member_api_docs
+  LiveContentResponse(
+      {this.modelTurn,
+      this.responseStatus = LiveResponseStatus.normal,
+      this.functionCalls,
+      this.functionIdsToCancel});
+
+  /// The content generated by the live model.
+  final Content? modelTurn;
+
+  /// The status of the live generation at the point this response was received.
+  /// Indicates whether the generation is ongoing, interrupted, or complete for
+  /// the current turn. Defaults to [LiveResponseStatus.normal].
+  final LiveResponseStatus responseStatus;
+
+  /// The list of function calls to be executed.
+  final List<FunctionCall>? functionCalls;
+
+  /// The list of [FunctionCall.id] to cancel.
+  final List<String>? functionIdsToCancel;
+}
+
 /// Represents realtime input from the client in a live stream.
 class LiveClientRealtimeInput {
   /// Creates a [LiveClientRealtimeInput] instance.