Misc fixes to search and UI.

- Use prefContext to create preference.
- rename "Gestures" to "Gesture shortcuts"
- Add search keyword to individual gesture settings so when search
  "gesture" they also show up.
- call super() for all getNonIndexableKeys() in search provider

Fix: 38327387
Fix: 36621897
Fix: 36685646
Test: make RunSettingsRoboTests

Change-Id: Ia5ddfeae08cb27c278dfb8d2376594e21d8f283c

src/com/android/settings/connecteddevice/ConnectedDeviceDashboardFragment.java

@@ -131,9 +131,8 @@ public class ConnectedDeviceDashboardFragment extends DashboardFragment {
 
                 @Override
                 public List<String> getNonIndexableKeys(Context context) {
+                    final List<String> keys = super.getNonIndexableKeys(context);
                     PackageManager pm = context.getPackageManager();
-                    final List<String> keys = new ArrayList<String>();
-
                     if (!pm.hasSystemFeature(PackageManager.FEATURE_NFC)) {
                         keys.add(NfcPreferenceController.KEY_TOGGLE_NFC);
                         keys.add(NfcPreferenceController.KEY_ANDROID_BEAM_SETTINGS);