libbb2 is not available in a public NDK yet. In order to be able to compile NFC for
BlackBerry 10 with a public NDK the BB10 implementation for the QNearfieldShareManager is only
built if libbb2 is detected.

Change-Id: Idd11d4584215fade91db9f79895f901547bce3ef
Reviewed-by: Stuart Burge <sburge@blackberry.com>
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>
Reviewed-by: Wolfgang Bremer <wbremer@blackberry.com>