chore: add missing toolCallbacks(vargs) to vertex chat options

Signed-off-by: Gareth Evans <[email protected]>

Author: garethjevans

models/spring-ai-vertex-ai-gemini/src/main/java/org/springframework/ai/vertexai/gemini/VertexAiGeminiChatOptions.java

@@ -16,6 +16,7 @@
 
 package org.springframework.ai.vertexai.gemini;
 
+import java.util.Arrays;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -456,6 +457,12 @@ public Builder toolCallbacks(List<FunctionCallback> toolCallbacks) {
 			return this;
 		}
 
+		public Builder toolCallbacks(FunctionCallback... toolCallbacks) {
+			Assert.notNull(toolCallbacks, "toolCallbacks cannot be null");
+			this.options.toolCallbacks.addAll(Arrays.asList(toolCallbacks));
+			return this;
+		}
+
 		@Deprecated
 		public Builder functions(Set<String> functionNames) {
 			return this.toolNames(functionNames);