Revert back to using DRA repository for ML artifacts (elastic#94655)

x-pack/plugin/ml/build.gradle

@@ -1,3 +1,6 @@
+import org.elasticsearch.gradle.VersionProperties
+import org.elasticsearch.gradle.internal.dra.DraResolvePlugin
+
 apply plugin: 'elasticsearch.internal-es-plugin'
 apply plugin: 'elasticsearch.internal-cluster-test'
 apply plugin: 'elasticsearch.internal-test-artifact'
@@ -11,27 +14,42 @@ esplugin {
   extendedPlugins = ['x-pack-autoscaling', 'lang-painless']
 }
 
+def localRepo = providers.systemProperty('build.ml_cpp.repo').orNull
 if (useDra == false) {
   repositories {
     exclusiveContent {
+      filter {
+        includeGroup 'org.elasticsearch.ml'
+      }
       forRepository {
         ivy {
           name "ml-cpp"
-          url providers.systemProperty('build.ml_cpp.repo').orElse('https://prelert-artifacts.s3.amazonaws.com').get()
           metadataSources {
             // no repository metadata, look directly for the artifact
             artifact()
           }
-          patternLayout {
-            artifact "maven/org/elasticsearch/ml/ml-cpp/[revision]/[module]-[revision](-[classifier]).[ext]"
+          if (localRepo) {
+            url localRepo
+            patternLayout {
+              artifact "maven/[orgPath]/[module]/[revision]/[module]-[revision](-[classifier]).[ext]"
+            }
+          } else {
+            url "https://artifacts-snapshot.elastic.co/"
+            patternLayout {
+              if (VersionProperties.isElasticsearchSnapshot()) {
+                artifact '/ml-cpp/[revision]/downloads/ml-cpp/[module]-[revision]-[classifier].[ext]'
+              } else {
+                // When building locally we always use snapshot artifacts even if passing `-Dbuild.snapshot=false`.
+                // Release builds are always done with a local repo.
+                artifact '/ml-cpp/[revision]-SNAPSHOT/downloads/ml-cpp/[module]-[revision]-SNAPSHOT-[classifier].[ext]'
+              }
+            }
           }
         }
       }
-      filter {
-        includeGroup 'org.elasticsearch.ml'
-      }
     }
   }
+
 }
 
 configurations {
@@ -115,4 +133,4 @@ tasks.named("dependencyLicenses").configure {
   mapping from: /lucene-.*/, to: 'lucene'
 }
 
-addQaCheckDependencies(project)
+addQaCheckDependencies(project)