Merge Copyable into Sliceable.

It's only a slice concept. Regular preference copyability is handled in
xml.

Bug: 112427717
Test: rebuild
Change-Id: Iaba7077c320cd03a5963797916a60e0dc80fdbbe

src/com/android/settings/slices/SliceBuilderUtils.java

@@ -93,7 +93,7 @@ public class SliceBuilderUtils {
             return buildUnavailableSlice(context, sliceData);
         }
 
-        if (controller instanceof Copyable) {
+        if (controller.isCopyableSlice()) {
             return buildCopyableSlice(context, sliceData, controller);
         }