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/Sliceable.java

@@ -50,6 +50,8 @@ public interface Sliceable {
      * - Must be understandable as a stand-alone Setting.
      * <p>
      * This does not guarantee the setting is available.
+     * <p>
+     * {@link #getSliceHighlightMenuRes} should also be overridden when returning true.
      *
      * @return {@code true} if the controller should be used as a Slice.
      */
@@ -131,4 +133,12 @@ public interface Sliceable {
     default Class<? extends SliceBackgroundWorker> getBackgroundWorkerClass() {
         return null;
     }
+
+    /**
+     * @return a resource ID that indicates which menu entry should be highlighted in multi-pane
+     * mode.
+     */
+    default int getSliceHighlightMenuRes() {
+        return 0;
+    }
 }