chore(*): change snackbar class name selector name changed

Author: mddragnev

projects/igniteui-angular/src/lib/grids/grid/grid.component.html

@@ -231,7 +231,7 @@
     </div>
     <div class="igx-grid__scroll-end" [style.float]='"right"' [style.width.px]='pinnedWidth' [style.min-width.px]='pinnedWidth' [hidden]="pinnedWidth === 0 || isPinningToStart"></div>
 </div>
-<div class="igx-grid__grid-addrow-snackbar">
+<div class="igx-grid__addrow-snackbar">
     <igx-snackbar #addRowSnackbar [actionText]="snackbarActionText" displayTime='2000'>{{snackbarLabel}}</igx-snackbar>
 </div>