Re-enable BWC tests and adjust versions after elastic#77420 backport to 7.x (elastic#79144)

Author: fcofdez

build.gradle

@@ -132,9 +132,9 @@ tasks.register("verifyVersions") {
  * after the backport of the backcompat code is complete.
  */
 
-boolean bwc_tests_enabled = false
+boolean bwc_tests_enabled = true
 // place a PR link here when committing bwc changes:
-String bwc_tests_disabled_issue = "https://github.com/elastic/elasticsearch/pull/77420"
+String bwc_tests_disabled_issue = ""
 /*
  * FIPS 140-2 behavior was fixed in 7.11.0. Before that there is no way to run elasticsearch in a
  * JVM that is properly configured to be in fips mode with BCFIPS. For now we need to disable

server/src/main/java/org/elasticsearch/indices/recovery/RecoverySettings.java

@@ -30,8 +30,7 @@
 
 public class RecoverySettings {
     public static final Version SNAPSHOT_RECOVERIES_SUPPORTED_VERSION = Version.V_7_15_0;
-    // TODO: update after backport
-    public static final Version SEQ_NO_SNAPSHOT_RECOVERIES_SUPPORTED_VERSION = Version.V_8_0_0;
+    public static final Version SEQ_NO_SNAPSHOT_RECOVERIES_SUPPORTED_VERSION = Version.V_7_16_0;
 
     private static final Logger logger = LogManager.getLogger(RecoverySettings.class);