Fix default distro bwc tests

qa/full-cluster-restart/build.gradle

@@ -20,6 +20,7 @@
 
 import org.elasticsearch.gradle.Version
 import org.elasticsearch.gradle.testclusters.RestTestRunnerTask
+import org.elasticsearch.gradle.testclusters.TestDistribution
 
 apply plugin: 'elasticsearch.standalone-test'
 apply plugin: 'elasticsearch.testclusters'
@@ -35,13 +36,18 @@ for (Version bwcVersion : bwcVersions.indexCompatible) {
   String baseName = "v${bwcVersion}"
 
   testClusters {
+    String configuredTestDistribution = System.getProperty('tests.distribution', 'oss').toUpperCase()
     "${baseName}" {
+      testDistribution = configuredTestDistribution
       versions = [ bwcVersion.toString(), project.version ]
       numberOfNodes = 2
       // some tests rely on the translog not being flushed
       setting 'indices.memory.shard_inactive_time', '20m'
       setting 'http.content_type.required', 'true'
       setting 'path.repo', "${buildDir}/cluster/shared/repo/${baseName}"
+      if (configuredTestDistribution.equals("DEFAULT")) {
+        setting "xpack.security.enabled", "false"
+      }
       javaHome = project.file(project.ext.runtimeJavaHome)
     }
   }