private synchronized void finishCheck(LicenseValidator validator) {
        mChecksInProgress.remove(validator);
        if (mChecksInProgress.isEmpty()) {
            cleanupService();
        }
    }
Triggers the last deep link licensing URL returned from the server, which redirects users to a
page which enables them to gain access to the app. If no such URL is returned by the server, it
will go to the details page of the app in the Play Store.
android/android_framework/base/src/main/java/com/google/android/vending/licensing/LicenseChecker.java