keyguard: fix layout for sw320dp devices

800x480px dpi devices have less screen space than the xhdpi devices
Google designed the layout for and the layout needs adjustment.

- Reduce the lockscreen security container size such that the clock
  widget has enough space to display its content.
- In the SIM PIN/PUK view, Google put an empty widget on top, but
  we don't have space for that, increase its size such that the
  widget practically disappears.

This should not have any effect on devices with larger screens.

Ported from cm-10.2.
* Fix keyguard for mdpi devices too

Change-Id: I9e811cfd312abae24a9cad189d19e73848f6c4c1
keyguard: fix-fix layout for sw320dp devices

Default values need to be defined in sw360dp or larger devices will
pick up sw320dp values automatically.

On the maguro device the keyguard isn't properly centered.

- Before http://review.cyanogenmod.org/54758:
    http://i.imgur.com/F6sokhA.jpg
- After http://review.cyanogenmod.org/54758:
    http://i.imgur.com/OdTkZLL.jpg
- With this commit:
    http://i.imgur.com/TThq9da.jpg

Change-Id: Idcc29ec79a12e61b26d2ad5070468e70a8ef39df
Merge remote branch 'aokp/kitkat' into kitkat