Change compatibility version to 5.6 after backport

core/src/main/java/org/elasticsearch/search/SearchShardTarget.java

@@ -52,7 +52,7 @@ public final class SearchShardTarget implements Writeable, Comparable<SearchShar
         }
         shardId = ShardId.readShardId(in);
         this.originalIndices = null;
-        if (in.getVersion().onOrAfter(Version.V_6_0_0_beta1)) {
+        if (in.getVersion().onOrAfter(Version.V_5_6_0)) {
             clusterAlias = in.readOptionalString();
         } else {
             clusterAlias = null;
@@ -114,7 +114,7 @@ public final class SearchShardTarget implements Writeable, Comparable<SearchShar
             out.writeText(nodeId);
         }
         shardId.writeTo(out);
-        if (out.getVersion().onOrAfter(Version.V_6_0_0_beta1)) {
+        if (out.getVersion().onOrAfter(Version.V_5_6_0)) {
             out.writeOptionalString(clusterAlias);
         }
     }

core/src/main/java/org/elasticsearch/search/internal/ShardSearchLocalRequest.java

@@ -199,7 +199,7 @@ public class ShardSearchLocalRequest implements ShardSearchRequest {
         }
         nowInMillis = in.readVLong();
         requestCache = in.readOptionalBoolean();
-        if (in.getVersion().onOrAfter(Version.V_6_0_0_beta1)) {
+        if (in.getVersion().onOrAfter(Version.V_5_6_0)) {
             clusterAlias = in.readOptionalString();
         }
     }
@@ -221,7 +221,7 @@ public class ShardSearchLocalRequest implements ShardSearchRequest {
             out.writeVLong(nowInMillis);
         }
         out.writeOptionalBoolean(requestCache);
-        if (out.getVersion().onOrAfter(Version.V_6_0_0_beta1)) {
+        if (out.getVersion().onOrAfter(Version.V_5_6_0)) {
             out.writeOptionalString(clusterAlias);
         }
     }