[ml] Fix randomize_seed versions and unmute BWC tests (elastic#50027)

... now that elastic#49990 has been backported.

Relates elastic#49990

Author: dimitris-athanasiou

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ml/dataframe/analyses/Classification.java

@@ -119,7 +119,7 @@ public Classification(StreamInput in) throws IOException {
         predictionFieldName = in.readOptionalString();
         numTopClasses = in.readOptionalVInt();
         trainingPercent = in.readDouble();
-        if (in.getVersion().onOrAfter(Version.CURRENT)) {
+        if (in.getVersion().onOrAfter(Version.V_7_6_0)) {
             randomizeSeed = in.readOptionalLong();
         } else {
             randomizeSeed = Randomness.get().nextLong();
@@ -163,7 +163,7 @@ public void writeTo(StreamOutput out) throws IOException {
         out.writeOptionalString(predictionFieldName);
         out.writeOptionalVInt(numTopClasses);
         out.writeDouble(trainingPercent);
-        if (out.getVersion().onOrAfter(Version.CURRENT)) {
+        if (out.getVersion().onOrAfter(Version.V_7_6_0)) {
             out.writeOptionalLong(randomizeSeed);
         }
     }
@@ -180,7 +180,7 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
             builder.field(PREDICTION_FIELD_NAME.getPreferredName(), predictionFieldName);
         }
         builder.field(TRAINING_PERCENT.getPreferredName(), trainingPercent);
-        if (version.onOrAfter(Version.CURRENT)) {
+        if (version.onOrAfter(Version.V_7_6_0)) {
             builder.field(RANDOMIZE_SEED.getPreferredName(), randomizeSeed);
         }
         builder.endObject();

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ml/dataframe/analyses/Regression.java

@@ -91,7 +91,7 @@ public Regression(StreamInput in) throws IOException {
         boostedTreeParams = new BoostedTreeParams(in);
         predictionFieldName = in.readOptionalString();
         trainingPercent = in.readDouble();
-        if (in.getVersion().onOrAfter(Version.CURRENT)) {
+        if (in.getVersion().onOrAfter(Version.V_7_6_0)) {
             randomizeSeed = in.readOptionalLong();
         } else {
             randomizeSeed = Randomness.get().nextLong();
@@ -130,7 +130,7 @@ public void writeTo(StreamOutput out) throws IOException {
         boostedTreeParams.writeTo(out);
         out.writeOptionalString(predictionFieldName);
         out.writeDouble(trainingPercent);
-        if (out.getVersion().onOrAfter(Version.CURRENT)) {
+        if (out.getVersion().onOrAfter(Version.V_7_6_0)) {
             out.writeOptionalLong(randomizeSeed);
         }
     }
@@ -146,7 +146,7 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
             builder.field(PREDICTION_FIELD_NAME.getPreferredName(), predictionFieldName);
         }
         builder.field(TRAINING_PERCENT.getPreferredName(), trainingPercent);
-        if (version.onOrAfter(Version.CURRENT)) {
+        if (version.onOrAfter(Version.V_7_6_0)) {
             builder.field(RANDOMIZE_SEED.getPreferredName(), randomizeSeed);
         }
         builder.endObject();

x-pack/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/mixed_cluster/90_ml_data_frame_analytics_crud.yml

@@ -1,8 +1,3 @@
-setup:
-  - skip:
-      version: "all"
-      reason:  "Until backport of https://github.com/elastic/elasticsearch/issues/49690"
-
 ---
 "Get old outlier_detection job":
 
@@ -65,6 +60,7 @@ setup:
   - match: { data_frame_analytics.0.dest.index: "old_cluster_regression_job_results" }
   - match: { data_frame_analytics.0.analysis.regression.dependent_variable: "foo" }
   - match: { data_frame_analytics.0.analysis.regression.training_percent: 100.0 }
+  - is_true: data_frame_analytics.0.analysis.regression.randomize_seed
 
 ---
 "Get old regression job stats":

x-pack/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/old_cluster/90_ml_data_frame_analytics_crud.yml

@@ -1,7 +1,4 @@
 setup:
-  - skip:
-      version: "all"
-      reason:  "Until backport of https://github.com/elastic/elasticsearch/issues/49690"
 
   - do:
       index:

x-pack/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/upgraded_cluster/90_ml_data_frame_analytics_crud.yml

@@ -1,8 +1,3 @@
-setup:
-  - skip:
-      version: "all"
-      reason:  "Until backport of https://github.com/elastic/elasticsearch/issues/49690"
-
 ---
 "Get old cluster outlier_detection job":
 
@@ -45,6 +40,7 @@ setup:
   - match: { data_frame_analytics.0.dest.index: "old_cluster_regression_job_results" }
   - match: { data_frame_analytics.0.analysis.regression.dependent_variable: "foo" }
   - match: { data_frame_analytics.0.analysis.regression.training_percent: 100.0 }
+  - is_true: data_frame_analytics.0.analysis.regression.randomize_seed
 
 ---
 "Get old cluster regression job stats":