Clean up search fragment loader lifecycle.

- Programatically create SearchView to make it always expand across
  entire action bar.
- Store current query text during screen rotation
- Restart loader when query text changes

Bug: 33354491
Test: RunSettingsRoboTests
Change-Id: I63838a38514569aac60c5d67ac52ac06a7acd5a3

src/com/android/settings/dashboard/DashboardSummary.java

@@ -22,7 +22,6 @@ import android.os.AsyncTask;
 import android.os.Bundle;
 import android.os.Handler;
 import android.support.v7.widget.LinearLayoutManager;
-import android.support.v7.widget.SimpleItemAnimator;
 import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.View;