Switch default value of spring.aop.proxy-target-class

This commit ensures that the default proxying value matches the opinion we
have applied for `@EnableTransactionManagement`

Closes gh-8786

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/aop/AopAutoConfiguration.java

 /*
- * 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.
@@ -45,14 +45,14 @@ public class AopAutoConfiguration {
 
 	@Configuration
 	@EnableAspectJAutoProxy(proxyTargetClass = false)
-	@ConditionalOnProperty(prefix = "spring.aop", name = "proxy-target-class", havingValue = "false", matchIfMissing = true)
+	@ConditionalOnProperty(prefix = "spring.aop", name = "proxy-target-class", havingValue = "false", matchIfMissing = false)
 	public static class JdkDynamicAutoProxyConfiguration {
 
 	}
 
 	@Configuration
 	@EnableAspectJAutoProxy(proxyTargetClass = true)
-	@ConditionalOnProperty(prefix = "spring.aop", name = "proxy-target-class", havingValue = "true", matchIfMissing = false)
+	@ConditionalOnProperty(prefix = "spring.aop", name = "proxy-target-class", havingValue = "true", matchIfMissing = true)
 	public static class CglibAutoProxyConfiguration {
 
 	}

spring-boot-autoconfigure/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -43,7 +43,7 @@
     "name": "spring.aop.proxy-target-class",
     "type": "java.lang.Boolean",
     "description": "Whether subclass-based (CGLIB) proxies are to be created (true) as opposed to standard Java interface-based proxies (false).",
-    "defaultValue": false
+    "defaultValue": true
   },
   {
     "name": "spring.application.admin.enabled",

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/aop/AopAutoConfigurationTests.java

@@ -60,7 +60,7 @@ public class AopAutoConfigurationTests {
 	@Test
 	public void aopWithDefaultSettings() {
 		load(TestConfiguration.class);
-		testProxyTargetClassDisabled();
+		testProxyTargetClassEnabled();
 	}
 
 	@Test

spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc

@@ -50,7 +50,7 @@ content into your application; rather pick only the properties that you need.
 
 	# AOP
 	spring.aop.auto=true # Add @EnableAspectJAutoProxy.
-	spring.aop.proxy-target-class=false # Whether subclass-based (CGLIB) proxies are to be created (true) as opposed to standard Java interface-based proxies (false).
+	spring.aop.proxy-target-class=true # Whether subclass-based (CGLIB) proxies are to be created (true) as opposed to standard Java interface-based proxies (false).
 
 	# IDENTITY ({sc-spring-boot}/context/ContextIdApplicationContextInitializer.{sc-ext}[ContextIdApplicationContextInitializer])
 	spring.application.index= # Application index.