Double list in Bluetooth Settings

Paired devices are listed first (from cache), followed by unpaired ones.
A scan is only started on user request or when there is no paired device
(should it be when there is no paired *connected* device?).

Wrench icon only displayed for paired devices.

Wrench click listener no longer uses mDeviceSettings which is unreliable
with ListView view recycling.

Fixed blinking ProgressCategory when the category was first in the list.

Change-Id: Ie749883426c12bd354da64733bd04b00304bc1f5

src/com/android/settings/bluetooth/DevicePickerFragment.java

@@ -55,7 +55,7 @@ public final class DevicePickerFragment extends DeviceListPreferenceFragment {
     @Override
     public void onResume() {
         super.onResume();
-        addDevices();
+        addCachedDevices();
         mLocalAdapter.startScanning(true);
     }