Issue #3471287 by ckng: fixed media library grid thumbnail issue

build/css/overrides/claro/media-library.css

-mercury-dialog .media-library-views-form__rows {
-  display: grid;
-  grid-gap: 1rem;
-  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
-}
-
 /*
   The buttons within this form-actions element get moved to the bottom of the dialog.
   That doesn't stop this container from taking up space in the flexbox – preventing