To Leadbolt:
It turned out that com.pad.android.listener.AdListener; or com.Leadbolt.AdListener; collided with import com.google.ads.AdListener; which is the AdMob AdListener. That's why I couldn't add the import statement.
You should extend your documentation, so if your listener collides with any other ad networks, how to use it, because it's not obvious. MobFox is also using com.adsdk.sdk.AdListener.
To use your AdListener while using other ad networks' AdListeners, this is how my first line looks like:
public class MainActivity extends Activity implements AdListener, com.google.ads.AdListener {
The first one is MobFox, the second one is AdMob. I didn't implement leadbolt's AdListener, because I am using it in the code:
AdController myController = new AdController(act, MY_LB_SECTION_ID_BANNER_ALL, new com.pad.android.listener.AdListener() {
This way it's working.