Add ES 6.4.2 version (#33830)

Version and properties files

Author: polyfractal

server/src/main/java/org/elasticsearch/Version.java

@@ -178,6 +178,8 @@ public class Version implements Comparable<Version>, ToXContentFragment {
     public static final Version V_6_4_0 = new Version(V_6_4_0_ID, org.apache.lucene.util.Version.LUCENE_7_4_0);
     public static final int V_6_4_1_ID = 6040199;
     public static final Version V_6_4_1 = new Version(V_6_4_1_ID, org.apache.lucene.util.Version.LUCENE_7_4_0);
+    public static final int V_6_4_2_ID = 6040299;
+    public static final Version V_6_4_2 = new Version(V_6_4_2_ID, org.apache.lucene.util.Version.LUCENE_7_4_0);
     public static final int V_6_5_0_ID = 6050099;
     public static final Version V_6_5_0 = new Version(V_6_5_0_ID, org.apache.lucene.util.Version.LUCENE_7_5_0);
 
@@ -196,6 +198,8 @@ public static Version fromId(int id) {
         switch (id) {
             case V_6_5_0_ID:
                 return V_6_5_0;
+            case V_6_4_2_ID:
+                return V_6_4_2;
             case V_6_4_1_ID:
                 return V_6_4_1;
             case V_6_4_0_ID: