fix(query-builder): test style name fix

Author: ivanvpetrov

projects/igniteui-angular/src/lib/query-builder/query-builder-functions.spec.ts

@@ -883,7 +883,8 @@ export class QueryBuilderFunctions {
 
     public static getDropGhost(fixture: ComponentFixture<any>): Element {
         var expressionsContainer = QueryBuilderFunctions.getQueryBuilderExpressionsContainer(fixture);
-        return expressionsContainer.querySelector(`div.${QueryBuilderSelectors.FILTER_TREE_EXPRESSION_ITEM_DROP_GHOST}`);
+        return expressionsContainer.querySelector(`div.${QueryBuilderSelectors.FILTER_TREE_EXPRESSION_ITEM_DROP_GHOST}`) ??
+            expressionsContainer.querySelector(`div.${QueryBuilderSelectors.FILTER_TREE_EXPRESSION_ITEM_KEYBOARD_GHOST}`);
     }
 
     public static getDropGhostBounds(fixture: ComponentFixture<any>): DOMRect {

projects/igniteui-angular/src/lib/query-builder/query-builder.common.ts

@@ -69,6 +69,7 @@ export const QueryBuilderSelectors = {
     FILTER_TREE_EXPRESSION_CONTEXT_MENU: IGX_FILTER_TREE + '__expression-context-menu',
     FILTER_TREE_EXPRESSION_ITEM: IGX_FILTER_TREE + '__expression-item',
     FILTER_TREE_EXPRESSION_ITEM_DROP_GHOST: IGX_FILTER_TREE + '__expression-item-drop-ghost',
+    FILTER_TREE_EXPRESSION_ITEM_KEYBOARD_GHOST: IGX_FILTER_TREE + '__expression-item-keyboard-ghost',
     FILTER_TREE_EXPRESSION_ITEM_GHOST: IGX_FILTER_TREE + '__expression-item-ghost',
     FILTER_TREE_EXPRESSION_SECTION: IGX_FILTER_TREE + '__expression-section',