Update Search recents behavior

- per UX request
- Search recents show now by defaults with the recent searches
when the SearchView is empty
- when we press on a Serach recent, we are showing the Search results
and the recents are disappearing
- when keying text in the SearchView, we hide the recents and start
showing the results
- we still save the Search query when hitting on a result

Change-Id: I6c2be21660a30f6973dea27d4852b2068a05963d

src/com/android/settings/SettingsActivity.java

@@ -1212,7 +1212,7 @@ public class SettingsActivity extends Activity
     @Override
     public boolean onQueryTextChange(String newText) {
         mSearchQuery = newText;
-        if (TextUtils.isEmpty(newText) || mSearchResultsFragment == null) {
+        if (mSearchResultsFragment == null) {
             return false;
         }
         return mSearchResultsFragment.onQueryTextChange(newText);