perf(ContactEdit): using Form (#8015)

src/contact-edit/test/__snapshots__/demo.spec.js.snap

@@ -2,7 +2,7 @@
 
 exports[`should render demo and match snapshot 1`] = `
 <div>
-  <div class="van-contact-edit">
+  <form class="van-form van-contact-edit">
     <div class="van-contact-edit__fields">
       <div class="van-cell van-field">
         <div class="van-cell__title van-field__label">
@@ -51,7 +51,7 @@ exports[`should render demo and match snapshot 1`] = `
       </div>
     </div>
     <div class="van-contact-edit__buttons">
-      <button type="button"
+      <button type="submit"
               class="van-button van-button--danger van-button--normal van-button--block van-button--round"
       >
         <div class="van-button__content">
@@ -70,6 +70,6 @@ exports[`should render demo and match snapshot 1`] = `
         </div>
       </button>
     </div>
-  </div>
+  </form>
 </div>
 `;