Update Settings search result unique ids

- SearchResult stableIds are now DocIds from the database
- DocIds are data reference key's hash, when the key is not
empty or null
- Otherwise, DocIds are a hashcode from a set of fields.

Change-Id: Id36f7bf4ceaaa3a2bd326ecafbfe97fd0b247df2
Fixes: 37327194
Test: make RunSettingsRoboTest

src/com/android/settings/search/SavedQueryLoader.java

@@ -68,8 +68,9 @@ public class SavedQueryLoader extends AsyncLoader<List<? extends SearchResult>>
             final SavedQueryPayload payload = new SavedQueryPayload(
                     cursor.getString(cursor.getColumnIndex(SavedQueriesColumns.QUERY)));
             results.add(new SearchResult.Builder()
-                    .addTitle(payload.query)
-                    .addPayload(payload)
+                    .setStableId(payload.hashCode())
+                    .setTitle(payload.query)
+                    .setPayload(payload)
                     .build());
         }
         return results;