Adapt bwc versions after backporting #31045 to 6.x

Author: bleskes

server/src/main/java/org/elasticsearch/persistent/PersistentTasksCustomMetaData.java

@@ -313,7 +313,7 @@ public PersistentTask(StreamInput in) throws IOException {
             id = in.readString();
             allocationId = in.readLong();
             taskName = in.readString();
-            if (in.getVersion().onOrAfter(Version.V_7_0_0_alpha1)) {
+            if (in.getVersion().onOrAfter(Version.V_6_4_0)) {
                 params = (P) in.readNamedWriteable(PersistentTaskParams.class);
             } else {
                 params = (P) in.readOptionalNamedWriteable(PersistentTaskParams.class);
@@ -328,7 +328,7 @@ public void writeTo(StreamOutput out) throws IOException {
             out.writeString(id);
             out.writeLong(allocationId);
             out.writeString(taskName);
-            if (out.getVersion().onOrAfter(Version.V_7_0_0_alpha1)) {
+            if (out.getVersion().onOrAfter(Version.V_6_4_0)) {
                 out.writeNamedWriteable(params);
             } else {
                 out.writeOptionalNamedWriteable(params);

server/src/main/java/org/elasticsearch/persistent/StartPersistentTaskAction.java

@@ -93,7 +93,7 @@ public void readFrom(StreamInput in) throws IOException {
             super.readFrom(in);
             taskId = in.readString();
             taskName = in.readString();
-            if (in.getVersion().onOrAfter(Version.V_7_0_0_alpha1)) {
+            if (in.getVersion().onOrAfter(Version.V_6_4_0)) {
                 params = in.readNamedWriteable(PersistentTaskParams.class);
             } else {
                 params = in.readOptionalNamedWriteable(PersistentTaskParams.class);
@@ -105,7 +105,7 @@ public void writeTo(StreamOutput out) throws IOException {
             super.writeTo(out);
             out.writeString(taskId);
             out.writeString(taskName);
-            if (out.getVersion().onOrAfter(Version.V_7_0_0_alpha1)) {
+            if (out.getVersion().onOrAfter(Version.V_6_4_0)) {
                 out.writeNamedWriteable(params);
             } else {
                 out.writeOptionalNamedWriteable(params);

server/src/test/java/org/elasticsearch/cluster/ClusterStateIT.java

@@ -33,7 +33,6 @@
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.io.stream.Writeable;
-import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
@@ -43,7 +42,6 @@
 import org.elasticsearch.script.ScriptService;
 import org.elasticsearch.test.ESIntegTestCase;
 import org.elasticsearch.threadpool.ThreadPool;
-import org.elasticsearch.transport.TcpTransport;
 import org.elasticsearch.watcher.ResourceWatcherService;
 
 import java.io.IOException;