Post visual update: Update the favorites item style (#6599)

Task/Issue URL:
https://app.asana.com/1/137249556945/project/1207418217763355/task/1210609571927331?focus=true

### Description

This PR updates the style of the favorites item on a NTP (new border and
corner radius).

Design:
<img width="350" height="1032" alt="image"
src="https://github.com/user-attachments/assets/8de6150d-8015-4a20-8cec-8b687b0f5dcb"
/>


### Steps to test this PR

_Feature 1_
- [ ] Load a website and add it to the favorite bookmarks
- [ ] Open a NTP
- [ ] Verify the favorite item matches the new design

### UI changes

<img width="350" height="2400" alt="image"
src="https://github.com/user-attachments/assets/e62fee40-e6d1-4ef4-a25a-3e6e5370ea7e"
/>

Author: 0nko

common/common-ui/src/main/res/drawable/background_dashed_outline.xml

@@ -20,5 +20,5 @@
         android:dashWidth="4dp"
         android:dashGap="4dp"
         android:color="?attr/daxColorLines" />
-    <corners android:radius="@dimen/smallShapeCornerRadius" />
+    <corners android:radius="@dimen/mediumShapeCornerRadius" />
 </shape>

saved-sites/saved-sites-impl/src/main/res/layout/view_favourite_section_item.xml

@@ -29,15 +29,17 @@
         android:layout_height="@dimen/gridItemImageSize"
         android:layout_gravity="center_horizontal"
         app:cardBackgroundColor="?attr/daxColorSurface"
-        app:cardCornerRadius="@dimen/smallShapeCornerRadius"
+        app:cardCornerRadius="@dimen/mediumShapeCornerRadius"
         tools:visibility="gone"
-        app:cardElevation="2dp">
+        app:cardElevation="0dp">
 
-        <ImageView
+        <com.google.android.material.imageview.ShapeableImageView
             android:id="@+id/quickAccessFavicon"
-            android:layout_width="@dimen/gridItemImageSize"
-            android:layout_height="@dimen/gridItemImageSize"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:padding="@dimen/keyline_2"
             android:layout_gravity="center"
+            app:shapeAppearanceOverlay="@style/Widget.DuckDuckGo.FavouritesItemFavicon"
             android:importantForAccessibility="no" />
 
     </com.google.android.material.card.MaterialCardView>

saved-sites/saved-sites-impl/src/main/res/values/styles-saved-sites.xml

@@ -21,4 +21,8 @@
         <item name="android:layout_height">match_parent</item>
         <item name="isExpandable">true</item>
     </style>
+    <style name="Widget.DuckDuckGo.FavouritesItemFavicon">
+        <item name="cornerFamily">rounded</item>
+        <item name="cornerSize">@dimen/smallShapeCornerRadius</item>
+    </style>
 </resources>