Bump 6.5 branch version to 6.5.3 (#36266)

Author: jaymode

buildSrc/version.properties

@@ -1,4 +1,4 @@
-elasticsearch     = 6.5.2
+elasticsearch     = 6.5.3
 lucene            = 7.5.0
 
 # optional dependencies

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

@@ -192,8 +192,10 @@ public class Version implements Comparable<Version>, ToXContentFragment {
     public static final Version V_6_5_1 = new Version(V_6_5_1_ID, org.apache.lucene.util.Version.LUCENE_7_5_0);
     public static final int V_6_5_2_ID = 6050299;
     public static final Version V_6_5_2 = new Version(V_6_5_2_ID, org.apache.lucene.util.Version.LUCENE_7_5_0);
+    public static final int V_6_5_3_ID = 6050399;
+    public static final Version V_6_5_3 = new Version(V_6_5_3_ID, org.apache.lucene.util.Version.LUCENE_7_5_0);
 
-    public static final Version CURRENT = V_6_5_2;
+    public static final Version CURRENT = V_6_5_3;
 
     static {
         assert CURRENT.luceneVersion.equals(org.apache.lucene.util.Version.LATEST) : "Version must be upgraded to ["
@@ -206,6 +208,8 @@ public static Version readVersion(StreamInput in) throws IOException {
 
     public static Version fromId(int id) {
         switch (id) {
+            case V_6_5_3_ID:
+                return V_6_5_3;
             case V_6_5_2_ID:
                 return V_6_5_2;
             case V_6_5_1_ID: