Add @FunctionalInterface to remaining public and protected interfaces

See gh-6857

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/AutoConfigurationImportFilter.java

@@ -39,6 +39,7 @@ import org.springframework.context.ResourceLoaderAware;
  * @author Phillip Webb
  * @since 1.5.0
  */
+@FunctionalInterface
 public interface AutoConfigurationImportFilter {
 
 	/**

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/AutoConfigurationImportListener.java

@@ -41,6 +41,7 @@ import org.springframework.context.ResourceLoaderAware;
  * @author Phillip Webb
  * @since 1.5.0
  */
+@FunctionalInterface
 public interface AutoConfigurationImportListener extends EventListener {
 
 	/**

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/cassandra/ClusterBuilderCustomizer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -27,6 +27,7 @@ import com.datastax.driver.core.Cluster.Builder;
  * @author Eddú Meléndez
  * @since 1.5.0
  */
+@FunctionalInterface
 public interface ClusterBuilderCustomizer {
 
 	/**

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/elasticsearch/jest/HttpClientConfigBuilderCustomizer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -27,6 +27,7 @@ import io.searchbox.client.config.HttpClientConfig.Builder;
  * @author Stephane Nicoll
  * @since 1.5.0
  */
+@FunctionalInterface
 public interface HttpClientConfigBuilderCustomizer {
 
 	/**

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/security/IgnoredRequestCustomizer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -25,6 +25,7 @@ import org.springframework.security.config.annotation.web.builders.WebSecurity.I
  * @author Madhura Bhave
  * @since 1.5.0
  */
+@FunctionalInterface
 public interface IgnoredRequestCustomizer {
 
 	/**

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/security/oauth2/resource/UserInfoRestTemplateFactory.java

@@ -26,6 +26,7 @@ import org.springframework.security.oauth2.client.OAuth2RestTemplate;
  * @author Stephane Nicoll
  * @since 1.4.0
  */
+@FunctionalInterface
 public interface UserInfoRestTemplateFactory {
 
 	/**

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/transaction/PlatformTransactionManagerCustomizer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -27,6 +27,7 @@ import org.springframework.transaction.PlatformTransactionManager;
  * @author Phillip Webb
  * @since 1.5.0
  */
+@FunctionalInterface
 public interface PlatformTransactionManagerCustomizer<T extends PlatformTransactionManager> {
 
 	/**