Add annotation and rename method

Author: nielsbauman

server/src/main/java/org/elasticsearch/cluster/ProjectState.java

@@ -80,7 +80,7 @@ public ClusterState updatedState(Consumer<ProjectMetadata.Builder> projectBuilde
      * Build a new {@link ClusterState} with the updated project.
      */
     public ClusterState updatedState(ProjectMetadata updatedProject) {
-        return ClusterState.builder(cluster).metadata(cluster.metadata().updateSingleProject(updatedProject)).build();
+        return ClusterState.builder(cluster).metadata(cluster.metadata().withUpdatedProject(updatedProject)).build();
     }
 
     /**

server/src/main/java/org/elasticsearch/cluster/metadata/Metadata.java

@@ -407,7 +407,9 @@ private Metadata updateSingleProject(Function<ProjectMetadata, ProjectMetadata>
     /**
      * Updates a single project in the metadata. This offers a more performant way of updating a single project compared to the Builder.
      */
-    public Metadata updateSingleProject(ProjectMetadata updatedProject) {
+    @FixForMultiProject // We should reconsider whether this method is valuable once we update Metadata.Builder to hold constructed projects
+    // instead of project builders.
+    public Metadata withUpdatedProject(ProjectMetadata updatedProject) {
         final var existingProject = projectMetadata.get(updatedProject.id());
         if (existingProject == null) {
             throw new IllegalArgumentException(
@@ -1532,7 +1534,7 @@ public Metadata copyAndUpdateProject(ProjectId projectId, Consumer<ProjectMetada
         }
         final var builder = ProjectMetadata.builder(existingProject);
         updater.accept(builder);
-        return updateSingleProject(builder.build());
+        return withUpdatedProject(builder.build());
     }
 
     public static class Builder {