Gallery2: Add AF Translations

Change-Id: I6171379ff19877d67dcee0fa1e1ec047ad7b6da0
Gallery2: SK translations

Change-Id: Id5b1737250575e9a78e019179cf96b9259e47518
Gallery2: CS translation

- added 20Mpx resolution
- fixed decimal separator (Czech did not use dot)
- added 18 and 8.2 Mpx resolutions

Change-Id: I1a1e702e447875a4ca4fd7e311d5975492e1de99