Merge pull request #14493 from rjernst/tar_extension

Change tar extension back to tar.gz instead of tgz

buildSrc/src/main/groovy/org/elasticsearch/gradle/test/ClusterFormationTasks.groovy

@@ -235,7 +235,7 @@ class ClusterFormationTasks {
 
     static void configureDistributionDependency(Project project, String distro) {
         String elasticsearchVersion = ElasticsearchProperties.version
-        String packaging = distro == 'tar' ? 'tgz' : distro
+        String packaging = distro == 'tar' ? 'tar.gz' : distro
         project.configurations {
             elasticsearchDistro
         }

distribution/tar/build.gradle

@@ -19,6 +19,7 @@
 
 task buildTar(type: Tar, dependsOn: dependencyFiles) {
   baseName = 'elasticsearch'
+  extension = 'tar.gz'
   with archivesFiles
   compression = Compression.GZIP
 }