[Settings] Code refactor - remove unused import lines

Remove some unused import lines within source code based on
https://source.android.com/setup/contribute/code-style

Bug: 182867979
Test: build pass
Change-Id: I76dbcfa9e5b435b2838401dfee15b12f472d07d0

src/com/android/settings/wifi/WifiDialogActivity.java

@@ -22,7 +22,6 @@ import android.content.Intent;
 import android.net.NetworkInfo;
 import android.net.wifi.WifiConfiguration;
 import android.net.wifi.WifiManager;
-import android.net.wifi.WifiManager.ActionListener;
 import android.os.Bundle;
 import android.util.Log;