Fix release build (#83720)

-  Add `es.index_mode_feature_flag_registered` feature flag to data-streams module's internalClusterTest task.
-  Add `es.random_sampler_feature_flag_registered` feature flag to xpack rest tests with security qa module.

Closes #83722

modules/data-streams/build.gradle

@@ -51,3 +51,9 @@ if (BuildParams.inFipsJvm){
   tasks.named("javaRestTest").configure{enabled = false }
   tasks.named("yamlRestTest").configure{enabled = false }
 }
+
+if (BuildParams.isSnapshotBuild() == false) {
+  tasks.named("internalClusterTest").configure {
+    systemProperty 'es.index_mode_feature_flag_registered', 'true'
+  }
+}

qa/mixed-cluster/build.gradle

@@ -43,6 +43,7 @@ BuildParams.bwcVersions.withWireCompatible { bwcVersion, baseName ->
         println "Upgrading one node to create a mixed cluster"
         if (BuildParams.isSnapshotBuild() == false) {
           baseCluster.get().nodes."${baseName}-0".systemProperty 'es.index_mode_feature_flag_registered', 'true'
+          baseCluster.get().nodes."${baseName}-0".systemProperty 'es.random_sampler_feature_flag_registered', 'true'
         }
         baseCluster.get().nextNodeToNextVersion()
         // Getting the endpoints causes a wait for the cluster
@@ -50,6 +51,7 @@ BuildParams.bwcVersions.withWireCompatible { bwcVersion, baseName ->
         println "Upgrading another node to create a mixed cluster"
         if (BuildParams.isSnapshotBuild() == false) {
           baseCluster.get().nodes."${baseName}-1".systemProperty 'es.index_mode_feature_flag_registered', 'true'
+          baseCluster.get().nodes."${baseName}-1".systemProperty 'es.random_sampler_feature_flag_registered', 'true'
         }
         baseCluster.get().nextNodeToNextVersion()
         nonInputProperties.systemProperty('tests.rest.cluster', baseCluster.map(c -> c.allHttpSocketURI.join(",")))

x-pack/qa/core-rest-tests-with-security/build.gradle

@@ -33,5 +33,6 @@ testClusters.matching { it.name == "integTest" }.configureEach {
   setting 'xpack.security.autoconfiguration.enabled', 'false'
   if (BuildParams.isSnapshotBuild() == false) {
     systemProperty 'es.index_mode_feature_flag_registered', 'true'
+    systemProperty 'es.random_sampler_feature_flag_registered', 'true'
   }
 }

x-pack/qa/runtime-fields/build.gradle

@@ -42,6 +42,7 @@ subprojects {
       setting 'xpack.security.enabled', 'false'
       if (BuildParams.isSnapshotBuild() == false) {
         systemProperty 'es.index_mode_feature_flag_registered', 'true'
+        systemProperty 'es.random_sampler_feature_flag_registered', 'true'
       }
     }