unit/gatt: Add TP/GAW/CL/BV-06-C test
unit/gatt: Add TP/GAW/CL/BV-06-C test

Verify that a Generic Attribute Profile client can reliably write
a characteristic selected by handle.

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