Support slice deep links highlighting menu entries

- Add an interface to get highlight menu key resource in Sliceable
- Force implementing the new interface in TogglePreferenceController and
  CustomSliceable at syntax level
- Update the slice index db schema

Bug: 204695404
Test: manual, robotest build pass, unit
Change-Id: I0b5068bccd04f1590023de7f3385bc0a4c6fa47b

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

@@ -103,6 +103,9 @@ public interface CustomSliceable extends Sliceable {
         return true;
     }
 
+    @Override
+    int getSliceHighlightMenuRes();
+
     /**
      * Build an instance of a {@link CustomSliceable} which has a {@link Context}-only constructor.
      */