fix(accordion): move styles to inner element to use proper animation (#30032)

Moves the padding to the inner content element so the `offsetHeight` will be calculated properly and the animation will be smooth.

core/src/components/accordion/accordion.ionic.scss

@@ -58,7 +58,7 @@
 // Accordion Content
 // --------------------------------------------------
 
-#content {
+#content-wrapper {
   @include globals.padding(null, globals.$ion-space-400, globals.$ion-space-300, globals.$ion-space-400);
   @include globals.typography(globals.$ion-body-md-regular);
 

core/src/components/accordion/test/shape/index.html

@@ -11,7 +11,7 @@
     <style>
       .grid {
         display: grid;
-        grid-template-columns: repeat(4, 1fr);
+        grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
         grid-row-gap: 20px;
         grid-column-gap: 20px;
       }