Implement Holo Light Theme for Settings

... and use Holo (Dark) Theme for the Drawer as requested by UX

Also remove the Wi-Fi and Bluetooth switches in the Drawer per
following UX specification.

Change-Id: I4fc17481255b5db337a887033bc831ded0d2d701

res/layout/settings_main.xml

@@ -76,6 +76,6 @@
               android:layout_width="300dp"
               android:layout_height="match_parent"
               android:layout_gravity="start"
-              android:background="#ff333333"/>
+              android:background="@color/background_drawer"/>
 
 </android.support.v4.widget.DrawerLayout>