Add .upper to admin CSS

@@ -1710,4 +1710,8 @@ a, input, textarea, select {
 .wp-admin.is-not-admin #icl_string_translations th:nth-child(4),
 .wp-admin.is-not-admin #icl_string_translations tbody td:nth-child(4) {
     display: none;
-}
\ No newline at end of file
+}
+
+.upper {
+    text-transform: uppercase;
+}