unit/test-gatt: Add TP/GAW/CL/BI-13-C test
unit/test-gatt: Add TP/GAW/CL/BI-13-C test

Verify Generic Attribute Profile client behavior when the Write
Long Characteristic Value procedure fails due to insufficient
encryption key size.

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