Adjust Feature States compatibility version following backport (#68945)

This PR adjusts the feature states compatibility version following the backport of #63513

Author: gwbrown

server/src/main/java/org/elasticsearch/snapshots/SnapshotsService.java

@@ -131,7 +131,7 @@ public class SnapshotsService extends AbstractLifecycleComponent implements Clus
 
     public static final Version OLD_SNAPSHOT_FORMAT = Version.V_7_5_0;
 
-    public static final Version FEATURE_STATES_VERSION = Version.V_8_0_0;
+    public static final Version FEATURE_STATES_VERSION = Version.V_7_12_0;
 
     private static final Logger logger = LogManager.getLogger(SnapshotsService.class);