Add indexing for SwitchPreferences

- now support the SwitchPreferences and save the "switchOn" and "switchOff"
attributes
- update Index database schema (and increment its version)
- fix an issue with some previous schema not rebuilt

Change-Id: I9cd48c666525f19474ef9bd5746d61b589058063

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

@@ -32,6 +32,8 @@ public class SearchIndexableRaw extends SearchIndexableData {
     public String summaryOn;
     public String summaryOff;
     public String entries;
+    public String switchOn;
+    public String switchOff;
     public String keywords;
 
     public String screenTitle;