update GA in popup

src/fe/mrna/index.html

         <h2 class="text-title">疫苗接種是幫助控制 COVID-19 的一種關鍵方法</h2>
         <p class="text">即刻了解並查詢接種院所資訊</p>
         <div class="button-group">
-          <a class="button-primary" href="https://pse.is/5gsrfp" target="_blank">
+          <a class="button-primary" data-gaEvent-category="popup" data-gaEvent-label="搜尋醫療院所"
+            href="https://pse.is/5gsrfp" target="_blank">
             <p>搜尋醫療院所</p>
           </a>
-          <a class="button-primary" href="https://pse.is/5gsrrx" target="_blank">
+          <a class="button-primary" data-gaEvent-category="popup" data-gaEvent-label="疫苗隨到隨打"
+            href="https://pse.is/5gsrrx" target="_blank">
             <p>疫苗隨到隨打</p>
           </a>
         </div>