Stops updates from the HAL, and unregisters the callback routines. After a call to stop, the previously registered callbacks must be considered invalid by the HAL. If stop is invoked without a previous 'init', this function should perform no work.
Initializes the interface and registers the callback routines with the HAL. After a successful call to 'init' the HAL must begin to provide updates at its own phase.
Status: GPS_MEASUREMENT_OPERATION_SUCCESS GPS_MEASUREMENT_ERROR_ALREADY_INIT - if a callback has already been registered without a corresponding call to 'close' GPS_MEASUREMENT_ERROR_GENERIC - if any other error occurred, it is expected that the HAL will not generate any updates upon returning this error code.