android/hal-gatt: Remove unneeded never read initialization
android/hal-gatt: Remove unneeded never read initialization

Fixes clang warning:
...
android/hal-gatt.c:1021:3: warning: Value stored to 'data' is never read
                data += service_uuid_len;
                ^       ~~~~~~~~~~~~~~~~
1 warning generated.
...

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