Add new layout for Slice half card

- Extract dismissal view as a layout xml and reuse it in half card
- fixed minor naming convention

This new layout is composed of custom views and the purpose is to
show slice in half width form in contextual homepage.

Bug: 119655434
Test: visual
Change-Id: I224d8bc1b7f95f969f6a134a316bd80b4cd013ee

src/com/android/settings/homepage/contextualcards/slices/SliceContextualCardRenderer.java

@@ -195,7 +195,7 @@ public class SliceContextualCardRenderer implements ContextualCardRenderer,
         public SliceViewHolder(View view) {
             super(view);
             sliceView = view.findViewById(R.id.slice_view);
-            viewFlipper = view.findViewById(R.id.viewFlipper);
+            viewFlipper = view.findViewById(R.id.view_flipper);
         }
 
         public void resetCard() {