Re-enable bwc tests now that #29538 has been backported and 6.x intake

build succeeded.

build.gradle

@@ -170,8 +170,8 @@ task verifyVersions {
  * the enabled state of every bwc task. It should be set back to true
  * after the backport of the backcompat code is complete.
  */
-final boolean bwc_tests_enabled = false
-final String bwc_tests_disabled_issue = "https://github.com/elastic/elasticsearch/pull/29538" /* place a PR link here when committing bwc changes */
+final 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/indices/alias/get/GetAliasesRequest.java

@@ -49,7 +49,7 @@ public class GetAliasesRequest extends MasterNodeReadRequest<GetAliasesRequest>
         indices = in.readStringArray();
         aliases = in.readStringArray();
         indicesOptions = IndicesOptions.readIndicesOptions(in);
-        if (in.getVersion().onOrAfter(Version.V_7_0_0_alpha1)) {
+        if (in.getVersion().onOrAfter(Version.V_6_4_0)) {
             originalAliases = in.readStringArray();
         }
     }
@@ -60,7 +60,7 @@ public class GetAliasesRequest extends MasterNodeReadRequest<GetAliasesRequest>
         out.writeStringArray(indices);
         out.writeStringArray(aliases);
         indicesOptions.writeIndicesOptions(out);
-        if (out.getVersion().onOrAfter(Version.V_7_0_0_alpha1)) {
+        if (out.getVersion().onOrAfter(Version.V_6_4_0)) {
             out.writeStringArray(originalAliases);
         }
     }