Implement the Copyable interface to PhoneNumberPreferenceController

Change-Id: I70085cffe13047ac808d1bf08a467f693b1d8737
Fixes: 118398321
Test: manual and robotests

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

@@ -94,7 +94,7 @@ public class SliceBuilderUtils {
             return buildUnavailableSlice(context, sliceData);
         }
 
-        if (controller instanceof CopyableSlice) {
+        if (controller instanceof Copyable) {
             return buildCopyableSlice(context, sliceData, controller);
         }