The MR adds implementations (+ a few tests) for the following methods in `bluetoothapis.h`:
* `BluetoothSdpEnumAttributes` * `BluetoothSdpGetContainerElementData` * `BluetoothSdpGetElementData` * `BluetoothSdpGetAttributeValue`
-- v18: bluetoothapis: Implement BluetoothSdpGetAttributeValue. bluetoothapis/tests: Add tests for BluetoothSdpGetAttributeValue. bluetoothapis: Add stub for BluetoothSdpGetAttributeValue. bluetoothapis: Implement BluetoothSdpEnumAttributes. bluetoothapis/tests: Add tests for BluetoothSdpEnumAttributes. bluetoothapis: Add stub for BluetoothSdpEnumAttributes. bluetoothapis: Implement BluetoothSdpGetContainerElementData. bluetoothapis/tests: Add tests for BluetoothSdpGetContainerElementData. bluetoothapis: Add stub for BluetoothSdpGetContainerElementData. bluetoothapis: Implement BluetoothSdpGetElementData. bluetoothapis/tests: Add tests for BluetoothSdpGetElementData.