Obtaining filter rate adjustment notification from C-V2X Throttle Manager API

Please follow bellow steps to obtain filter rate adjustment notification

### 1. Implement ICv2xThrottleManagerListener interface ###

class Cv2xTmListener : public ICv2xThrottleManagerListener {
    public:
        void onFilterRateAdjustment(int rate) override;
 };

### 2. Create a initialization status callback function

bool cv2xTmStatusUpdated = false;
telux::common::ServiceStatus cv2xTmStatus =
    telux::common::ServiceStatus::SERVICE_UNAVAILABLE;
std::condition_variable cv;
std::mutex mtx;

std::cout << "Running TM app" << std::endl;

auto statusCb = [&](telux::common::ServiceStatus status) {
    std::lock_guard<std::mutex> lock(mtx);
    cv2xTmStatusUpdated = true;
    cv2xTmStatus = status;
    cv.notify_all();
};

### 3. Get a handle to the ICv2xThrottleManager object ###

int main {
    // Get handle to Cv2xThrottleManager
    auto & cv2xFactory = Cv2xFactory::getInstance();
    auto cv2xThrottleManager = cv2xFactory.getCv2xThrottleManager(statusCb);

### 4. Wait for throttle manager to complete initialization ###

std::unique_lock<std::mutex> lck(mtx);
cv.wait(lck, [&] { return cv2xTmStatusUpdated; });
if (telux::common::ServiceStatus::SERVICE_AVAILABLE !=
    cv2xTmStatus) {
    std::cout << "Error: failed to initialize Cv2xThrottleManager." << std::endl;
    return EXIT_FAILURE;
}

### 5. Instantiate Cv2xTmListener ###

auto listener = std::make_shared<Cv2xTmListener>();

### 6. Register listener

if (cv2xThrottleManager->registerListener(listener) !=
    telux::common::Status::SUCCESS) {
        std::cout << "Failed to register listener" << std::endl;
        return EXIT_FAILURE;
}

7. Wait for filter rate adjustment notification

~~~~~~{.cpp} void Cv2xTmListener::onFilterRateAdjustment(int rate) { std::cout << "Updated rate: " << rate << std::endl; }