Update "Previous connected device" preference

1. Show up to 3 devices in main page
2. Add "See all" preference to go ot detail page

Bug: 116350449
Test: Screenshot && RunSettingsRoboTests
Change-Id: Iee0de8a2b7f2543e946a117ba2d9ca9dde6c8678

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

@@ -43,7 +43,8 @@ public class SavedBluetoothDeviceUpdater extends BluetoothDeviceUpdater
         final BluetoothDevice device = cachedDevice.getDevice();
         if (DBG) {
             Log.d(TAG, "isFilterMatched() device name : " + cachedDevice.getName() +
-                    ", is connected : " + device.isConnected());
+                    ", is connected : " + device.isConnected() + ", is profile connected : "
+                    + cachedDevice.isConnected());
         }
         return device.getBondState() == BluetoothDevice.BOND_BONDED && !device.isConnected();
     }