Improve trusted-set-local-storage-item scriptlet

Related discussion:
uBlockOrigin/uAssets@df1041c#commitcomment-141265533

Author: gorhill

assets/resources/scriptlets.js

@@ -1052,12 +1052,14 @@ function setLocalStorageItemFn(
     ];
 
     if ( trusted ) {
-        if ( value === '$now$' ) {
-            value = Date.now();
-        } else if ( value === '$currentDate$' ) {
-            value = `${Date()}`;
-        } else if ( value === '$currentISODate$' ) {
-            value = (new Date()).toISOString();
+        if ( value.includes('$now$') ) {
+            value.replaceAll('$now$', Date.now());
+        }
+        if ( value.includes('$currentDate$') ) {
+            value.replaceAll('$currentDate$', `${Date()}`);
+        }
+        if ( value.includes('$currentISODate$') ) {
+            value.replaceAll('$currentISODate$', (new Date()).toISOString());
         }
     } else {
         const normalized = value.toLowerCase();