Add dynamic Preferences indexing (part 2)

- change the Index SQL model. Add a new "enabled" column.
- use that column for issuing a more restrictive search query
- change the SearchIndexProvider API to pass the "enable" state
- apply it to Bluetooth settings
- refactor the list of indexable resources (SearchIndexableResources)

Change-Id: Ic900fb27cb12a285a80d953aa1aa88f0070cd986

src/com/android/settings/wifi/WifiSettings.java

@@ -1168,12 +1168,13 @@ public class WifiSettings extends RestrictedSettingsFragment
     public static final SearchIndexProvider SEARCH_INDEX_DATA_PROVIDER =
         new SearchIndexProvider() {
             @Override
-            public List<SearchIndexableResource> getXmlResourcesToIndex(Context context) {
+            public List<SearchIndexableResource> getXmlResourcesToIndex(
+                    Context context, boolean enabled) {
                 return null;
             }
 
             @Override
-            public List<SearchIndexableRaw> getRawDataToIndex(Context context) {
+            public List<SearchIndexableRaw> getRawDataToIndex(Context context, boolean enabled) {
                 final List<SearchIndexableRaw> result = new ArrayList<SearchIndexableRaw>();
                 final Resources res = context.getResources();