Introduce special UI modes for night and car usage.

The device mode is now called ui mode. Furthermore is the order of
precedence for the resources now in such a way that the ui mode needs
to be specified after the orientation and before the density.

The ui mode can be set, like it is done for the locale, as follows:

IActivityManager am = ActivityManagerNative.getDefault();
Configuration config = am.getConfiguration();
config.uiMode = Configuration.UI_MODE_TYPE_CAR | Configuration.UI_MODE_NIGHT_ANY;
am.updateConfiguration(config);

To allow users to disable the car mode and set the night mode the IUiModeManager
interface is used.

The automatic night mode switching will be added in a separate change.