Make QBS setings constants accessible for other plugins.

Change-Id: I7e66136d2b75a932b981713ccc27e3e69fd44baa
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>
Export android specific settings to QBS

Change-Id: I3640272dc027047a1d27a2b55329c9f5093e8f1f
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>