Work with array list instead of list for performance reasons (#4297)

Signed-off-by: Maxim Nesen <maxim.nesen@oracle.com>

Author: senivam

core-server/src/main/java/org/glassfish/jersey/server/model/Resource.java

@@ -200,7 +200,7 @@ public static final class Builder {
         private Builder(final Resource.Builder parentResource) {
             this.methodBuilders = new LinkedHashSet<>();
             this.childResourceBuilders = new LinkedHashSet<>();
-            this.childResources = new LinkedList<>();
+            this.childResources = new ArrayList<>();
             this.resourceMethods = new LinkedList<>();
             this.handlerClasses = Collections.newSetFromMap(new IdentityHashMap<>());
             this.handlerInstances = Collections.newSetFromMap(new IdentityHashMap<>());
@@ -542,7 +542,7 @@ private void onBuildChildResource(Builder childResourceBuilder, Resource.Data ch
 
         }
 
-        private List<Resource.Data> mergeResources(List<Resource.Data> resources) {
+        private static List<Resource.Data> mergeResources(List<Resource.Data> resources) {
             List<Resource.Data> mergedResources = new ArrayList<>();
             for (int i = 0; i < resources.size(); i++) {
                 Resource.Data outer = resources.get(i);