The _gatt_ infix was determined to be unnecessary as
GATT is implied by it being a Bluetooth service.
Signed-off-by: Emil Gydesen <emil.gydesen@nordicsemi.no>
This commit moves the BLE GATT heart rate service from
samples/bluetooth/gatt to subsys/bluetooth/services and adds a Kconfig
entry to enable and configure the service.
Signed-off-by: Joakim Andersson <joakim.andersson@nordicsemi.no>