Add META-INF/LICENSE.txt to published jars

Closes gh-17638

buildSrc/src/main/groovy/io/spring/gradle/convention/SpringModulePlugin.groovy

@@ -19,6 +19,7 @@ package io.spring.gradle.convention;
 import org.gradle.api.Project
 import org.gradle.api.plugins.JavaLibraryPlugin;
 import org.gradle.api.plugins.PluginManager
+import org.gradle.api.tasks.bundling.Jar
 import org.springframework.gradle.classpath.CheckClasspathForProhibitedDependenciesPlugin;
 import org.springframework.gradle.maven.SpringMavenPlugin;
 
@@ -41,6 +42,10 @@ class SpringModulePlugin extends AbstractSpringJavaPlugin {
 		if (!Utils.isRelease(project)) {
 			deployArtifacts.dependsOn project.tasks.artifactoryPublish
 		}
+		project.tasks.withType(Jar) {
+			from(project.rootProject.files('LICENSE.txt'))
+			into('META-INF')
+		}
 	}
 
 }