core: Add a variable to track passive scanning
core: Add a variable to track passive scanning

This patch adds a state variable to track passive scanning and ensures
that LE connections are only created through this discovery procedure
and not the normal (StartDiscovery based) discovery procedure.

silent-snowman/bluez,pkarasev3/bluez,ComputeCycles/bluez,mapfau/bluez,ComputeCycles/bluez,pkarasev3/bluez,mapfau/bluez,pstglia/external-bluetooth-bluez,silent-snowman/bluez,mapfau/bluez,pstglia/external-bluetooth-bluez,pstglia/external-bluetooth-bluez,pkarasev3/bluez,silent-snowman/bluez,ComputeCycles/bluez,pkarasev3/bluez,ComputeCycles/bluez,mapfau/bluez,pstglia/external-bluetooth-bluez,silent-snowman/bluez