chore: make ToolConfirmation extend JsonBaseModel

PiperOrigin-RevId: 850747911

Author: google-genai-bot

core/src/main/java/com/google/adk/tools/ToolConfirmation.java

@@ -19,14 +19,15 @@
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.google.adk.JsonBaseModel;
 import com.google.auto.value.AutoValue;
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import javax.annotation.Nullable;
 
 /** Represents a tool confirmation configuration. */
 @AutoValue
 @JsonDeserialize(builder = ToolConfirmation.Builder.class)
-public abstract class ToolConfirmation {
+public abstract class ToolConfirmation extends JsonBaseModel {
 
   @Nullable
   @JsonProperty("hint")