Bootstrap initial versions to simplify transport version migration (elastic#134084)

This reverts our other bootstrapping of file-based transport versions
to make migration simpler moving forward and adds the initial version
one prior to the last initial version for each of 9.1, 9.0, 8.19, and 8.18.

Author: jdconrad

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

@@ -173,6 +173,7 @@ static TransportVersion def(int id) {
     public static final TransportVersion ESQL_SKIP_ES_INDEX_SERIALIZATION = def(8_827_0_00);
     public static final TransportVersion ADD_INDEX_BLOCK_TWO_PHASE = def(8_828_0_00);
     public static final TransportVersion RESOLVE_CLUSTER_NO_INDEX_EXPRESSION = def(8_829_0_00);
+    public static final TransportVersion ML_ROLLOVER_LEGACY_INDICES = def(8_830_0_00);
     public static final TransportVersion ADD_INCLUDE_FAILURE_INDICES_OPTION = def(8_831_0_00);
     public static final TransportVersion ESQL_RESPONSE_PARTIAL = def(8_832_0_00);
     public static final TransportVersion RANK_DOC_OPTIONAL_METADATA_FOR_EXPLAIN = def(8_833_0_00);
@@ -189,7 +190,6 @@ static TransportVersion def(int id) {
     public static final TransportVersion INITIAL_ELASTICSEARCH_8_18_2 = def(8_840_0_04);
     public static final TransportVersion INITIAL_ELASTICSEARCH_8_18_3 = def(8_840_0_05);
     public static final TransportVersion INITIAL_ELASTICSEARCH_8_18_4 = def(8_840_0_06);
-    public static final TransportVersion INITIAL_ELASTICSEARCH_8_18_6 = def(8_840_0_08);
     public static final TransportVersion INITIAL_ELASTICSEARCH_8_18_7 = def(8_840_0_09);
 
     /*

server/src/main/resources/transport/definitions/referable/ml_rollover_legacy_indices.csv

@@ -0,0 +1 @@
+8840008

server/src/main/resources/transport/definitions/unreferable/initial_elasticsearch_8_18_6.csv

@@ -1 +1 @@
-initial_elasticsearch_8_18_5,8840007
+initial_elasticsearch_8_18_6,8840008

server/src/main/resources/transport/upper_bounds/8.18.csv

@@ -40,6 +40,7 @@
 import java.util.Arrays;
 import java.util.List;
 
+import static org.elasticsearch.TransportVersions.ML_ROLLOVER_LEGACY_INDICES;
 import static org.elasticsearch.xpack.core.ClientHelper.ML_ORIGIN;
 import static org.elasticsearch.xpack.core.ml.utils.MlIndexAndAlias.FIRST_INDEX_SIX_DIGIT_SUFFIX;
 import static org.elasticsearch.xpack.core.ml.utils.MlIndexAndAlias.has6DigitSuffix;
@@ -52,8 +53,6 @@ public class MlAnomaliesIndexUpdate implements MlAutoUpdateService.UpdateAction
 
     private static final Logger logger = LogManager.getLogger(MlAnomaliesIndexUpdate.class);
 
-    private static final TransportVersion ML_ROLLOVER_LEGACY_INDICES = TransportVersion.fromName("ml_rollover_legacy_indices");
-
     private final IndexNameExpressionResolver expressionResolver;
     private final OriginSettingClient client;
 
@@ -66,7 +65,7 @@ public MlAnomaliesIndexUpdate(IndexNameExpressionResolver expressionResolver, Cl
     public boolean isMinTransportVersionSupported(TransportVersion minTransportVersion) {
         // Automatic rollover does not require any new features
         // but wait for all nodes to be upgraded anyway
-        return minTransportVersion.supports(ML_ROLLOVER_LEGACY_INDICES);
+        return minTransportVersion.onOrAfter(ML_ROLLOVER_LEGACY_INDICES);
     }
 
     @Override

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/MlAnomaliesIndexUpdate.java

@@ -28,6 +28,7 @@
 import java.util.ArrayList;
 import java.util.List;
 
+import static org.elasticsearch.TransportVersions.ML_ROLLOVER_LEGACY_INDICES;
 import static org.elasticsearch.xpack.core.ClientHelper.ML_ORIGIN;
 
 /**
@@ -41,8 +42,6 @@ public class MlIndexRollover implements MlAutoUpdateService.UpdateAction {
 
     private static final Logger logger = LogManager.getLogger(MlIndexRollover.class);
 
-    private static final TransportVersion ML_ROLLOVER_LEGACY_INDICES = TransportVersion.fromName("ml_rollover_legacy_indices");
-
     public record IndexPatternAndAlias(String indexPattern, String alias) {}
 
     private final IndexNameExpressionResolver expressionResolver;