android/gatt: Fix handling signed write command from remote
android/gatt: Fix handling signed write command from remote

As per spec (BT spec 4.1 Vol[3], Part F, chapter 3.4.5.4) message which
should be taken to generate signature is opcode, handle and parameters

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