QuickSettings: add holo dark/light theme chooser (1/2) - WIP

This will add the possibility to choose wether the tiles will
be shown in Holo dark or Holo light theme

It is the work of RoLa which I am finishing for him

Change-Id: I8b2c8a9fef021e802ff038837621eb67cd53881a
Signed-off-by: Dirk Rettschlag <dirk.rettschlag@gmail.com>