MC-18709: [WYSIWYG]Spinner is Always Displayed on Media Gallery popup

- Fix static tests.

Author: YuliyaLabudova

app/code/Magento/Cms/Test/Mftf/ActionGroup/AdminCMSBlockContentActionGroup.xml

@@ -19,8 +19,10 @@
         <waitForPageLoad stepKey="waitForPageLoad"/>
         <attachFile selector="{{BlockSelectImageSection.uploadFile}}" userInput="{{image.file}}" stepKey="attachLogo"/>
         <waitForElementVisible selector="{{BlockSelectImageSection.addSelected}}" stepKey="waitForAddSelected"/>
+        <waitForLoadingMaskToDisappear stepKey="waitForLoadingMaskToDisappear2"/>
         <click  selector="{{BlockSelectImageSection.addSelected}}" stepKey="clickAddSelected"/>
         <waitForElementVisible selector="{{BlockInsertOrEditImageSection.ok}}" stepKey="waitForOkButton"/>
+        <waitForLoadingMaskToDisappear stepKey="waitForLoadingMaskToDisappear"/>
         <click  selector="{{BlockInsertOrEditImageSection.ok}}" stepKey="clickOk"/>
     </actionGroup>
 </actionGroups>

app/code/Magento/Cms/Test/Mftf/Section/CmsNewBlockBlockActionsSection.xml

@@ -41,6 +41,6 @@
     <section name="BlockSelectImageSection">
         <element name="uploadFile" type="input" selector="input.fileupload"/>
         <element name="addSelected" type="button" selector="#insert_files"/>
-        <element name="treeRoot" type="text" selector="//div[contains(@class, 'jstree')]//a[contains(text(), 'Storage Root')]"/>
+        <element name="treeRoot" type="text" selector="#root"/>
     </section>
 </sections>