Bug 1856388 - use valid ARIA role for moz-five-star r=reusable-compon…

…ents-reviewers,tgiles

Made the simple role change and cleaned up a couple warnings related to how `ifDefined` was being used

Differential Revision: https://phabricator.services.mozilla.com/D189827

toolkit/content/widgets/moz-five-star/moz-five-star.mjs

@@ -53,10 +53,12 @@ export default class MozFiveStar extends MozLitElement {
       />
       <div
         class="stars"
-        role="image"
-        data-l10n-id=${ifDefined(this.title ? null : "moz-five-star-rating")}
+        role="img"
+        data-l10n-id=${ifDefined(
+          this.title ? undefined : "moz-five-star-rating"
+        )}
         data-l10n-args=${ifDefined(
-          this.title ? null : JSON.stringify({ rating: this.rating ?? 0 })
+          this.title ? undefined : JSON.stringify({ rating: this.rating ?? 0 })
         )}
       >
         ${starFill.map(