Fix typo for includeLayerTools

See gh-21310

Author: kylehoehns

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/docs/asciidoc/packaging.adoc

@@ -547,7 +547,7 @@ If you wish to exclude this dependency, you can do so in the following manner:
 					<configuration>
 						<layers>
 							<enabled>true</enabled>
-							<includeLayerTools>false</enabled>
+							<includeLayerTools>false</includeLayerTools>
 						</layers>
 					</configuration>
 				</plugin>