Use code includes and tabs in MVC Config documentation

Additional fixes.

See gh-22171

framework-docs/src/main/java/org/springframework/docs/web/webmvc/mvcconfig/mvcconfigadvancedxml/MyPostProcessor.java

@@ -26,6 +26,7 @@ public class MyPostProcessor implements BeanPostProcessor {
 
 	public Object postProcessBeforeInitialization(Object bean, String name) throws BeansException {
 		// ...
+		return bean;
 	}
 }
 // end::snippet[]

framework-docs/src/main/java/org/springframework/docs/web/webmvc/mvcconfig/mvcconfigpathmatching/WebConfiguration.java

@@ -17,7 +17,9 @@ public class WebConfiguration implements WebMvcConfigurer {
 	}
 
 	private PathPatternParser patternParser() {
+		PathPatternParser pathPatternParser = new PathPatternParser();
 		// ...
+		return pathPatternParser;
 	}
 }
 // end::snippet[]

framework-docs/src/main/java/org/springframework/docs/web/webmvc/mvcconfig/mvcconfigvalidation/WebConfiguration.java

@@ -18,6 +18,7 @@ package org.springframework.docs.web.webmvc.mvcconfig.mvcconfigvalidation;
 
 import org.springframework.context.annotation.Configuration;
 import org.springframework.validation.Validator;
+import org.springframework.validation.beanvalidation.OptionalValidatorFactoryBean;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
 
 // tag::snippet[]
@@ -26,7 +27,9 @@ public class WebConfiguration implements WebMvcConfigurer {
 
 	@Override
 	public Validator getValidator() {
+		Validator validator = new OptionalValidatorFactoryBean();
 		// ...
+		return validator;
 	}
 }
 // end::snippet[]

framework-docs/src/main/kotlin/org/springframework/docs/web/webmvc/mvcconfig/mvcconfigadvancedxml/MyPostProcessor.kt

@@ -25,6 +25,7 @@ class MyPostProcessor : BeanPostProcessor {
 
 	override fun postProcessBeforeInitialization(bean: Any, name: String): Any {
 		// ...
+		return bean
 	}
 }
 // end::snippet[]

framework-docs/src/main/kotlin/org/springframework/docs/web/webmvc/mvcconfig/mvcconfiginterceptors/WebConfiguration.kt

@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+@file:Suppress("DEPRECATION")
 package org.springframework.docs.web.webmvc.mvcconfig.mvcconfiginterceptors
 
 import org.springframework.context.annotation.Configuration

framework-docs/src/main/kotlin/org/springframework/docs/web/webmvc/mvcconfig/mvcconfigpathmatching/WebConfiguration.kt

@@ -32,7 +32,9 @@ class WebConfiguration : WebMvcConfigurer {
 	}
 
 	fun patternParser(): PathPatternParser {
+		val pathPatternParser = PathPatternParser()
 		//...
+		return pathPatternParser
 	}
 }
 // end::snippet[]

framework-docs/src/main/kotlin/org/springframework/docs/web/webmvc/mvcconfig/mvcconfigvalidation/WebConfiguration.kt

@@ -18,6 +18,7 @@ package org.springframework.docs.web.webmvc.mvcconfig.mvcconfigvalidation
 
 import org.springframework.context.annotation.Configuration
 import org.springframework.validation.Validator
+import org.springframework.validation.beanvalidation.OptionalValidatorFactoryBean
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurer
 
 // tag::snippet[]
@@ -25,7 +26,9 @@ import org.springframework.web.servlet.config.annotation.WebMvcConfigurer
 class WebConfiguration : WebMvcConfigurer {
 
 	override fun getValidator(): Validator {
+		val validator = OptionalValidatorFactoryBean()
 		// ...
+		return validator
 	}
 }
 // end::snippet[]