PB-265: Video background for Banner

- fix banner video issue when autoplay false

Author: omiroshnichenko

app/code/Magento/PageBuilder/view/adminhtml/web/css/source/content-type/banner/_default.less

@@ -130,11 +130,6 @@
 
     [id*='jarallax-container'] {
         z-index: 0 !important;
-
-        > iframe,
-        > video {
-            z-index: 0 !important;
-        }
     }
 }