Update Thymeleaf 3 related versions in docs and sample

See gh-6991
Closes gh-7183

Author: wilkinsona

spring-boot-docs/src/main/asciidoc/howto.adoc

@@ -1465,7 +1465,7 @@ By default, `spring-boot-starter-thymeleaf` uses Thymeleaf 2.1. If you are using
 ----
 	<properties>
 		<thymeleaf.version>3.0.2.RELEASE</thymeleaf.version>
-		<thymeleaf-layout-dialect.version>2.0.3</thymeleaf-layout-dialect.version>
+		<thymeleaf-layout-dialect.version>2.0.4</thymeleaf-layout-dialect.version>
 	</properties>
 ----
 

spring-boot-samples/spring-boot-sample-web-thymeleaf3/pom.xml

@@ -17,8 +17,8 @@
 	</organization>
 	<properties>
 		<main.basedir>${basedir}/../..</main.basedir>
-		<thymeleaf.version>3.0.0.RELEASE</thymeleaf.version>
-		<thymeleaf-layout-dialect.version>2.0.0</thymeleaf-layout-dialect.version>
+		<thymeleaf.version>3.0.2.RELEASE</thymeleaf.version>
+		<thymeleaf-layout-dialect.version>2.0.4</thymeleaf-layout-dialect.version>
 	</properties>
 	<dependencies>
 		<dependency>