Reenable BwC Tests for #45780 (#45804)

* Now that #45780 is merged BwC tests can be reenabled

build.gradle

@@ -176,8 +176,8 @@ task verifyVersions {
  * after the backport of the backcompat code is complete.
  */
 
-boolean bwc_tests_enabled = false
-final String bwc_tests_disabled_issue = "https://github.com/elastic/elasticsearch/pull/45780" /* place a PR link here when committing bwc changes */
+boolean bwc_tests_enabled = true
+final String bwc_tests_disabled_issue = "" /* place a PR link here when committing bwc changes */
 if (bwc_tests_enabled == false) {
   if (bwc_tests_disabled_issue.isEmpty()) {
     throw new GradleException("bwc_tests_disabled_issue must be set when bwc_tests_enabled == false")

server/src/main/java/org/elasticsearch/action/admin/cluster/repositories/cleanup/TransportCleanupRepositoryAction.java

@@ -70,7 +70,7 @@ public final class TransportCleanupRepositoryAction extends TransportMasterNodeA
 
     private static final Logger logger = LogManager.getLogger(TransportCleanupRepositoryAction.class);
 
-    private static final Version MIN_VERSION = Version.V_8_0_0;
+    private static final Version MIN_VERSION = Version.V_7_4_0;
 
     private final RepositoriesService repositoriesService;
 

server/src/main/java/org/elasticsearch/cluster/RepositoryCleanupInProgress.java

@@ -87,7 +87,7 @@ public final class RepositoryCleanupInProgress extends AbstractNamedDiffable<Clu
 
     @Override
     public Version getMinimalSupportedVersion() {
-        return Version.V_8_0_0;
+        return Version.V_7_4_0;
     }
 
     public static final class Entry implements Writeable {