Fix bug #17250939 Stability: ANRs in Settings: at...

Fix bug #17250939 Stability: ANRs in Settings: at com.android.settings.search.Index.updateInternal(Index.java:518)

- do not care about getting a result for updating the Index as
there is no way to make it useful (the result will come later
when this is no more relevant)
- make a copy of the data to process and pass it to the AsyncTask

Change-Id: I6b8a08ecbe3d32cffac1314c03f682ebacfd64bf