TetheringUtils jni - clazz type is jclass

See: packages/modules/Connectivity/Tethering/src/com/android/networkstack/tethering/util/TetheringUtils.java

public static native void setupNaSocket(FileDescriptor fd) throws SocketException;
public static native void setupNsSocket(FileDescriptor fd) throws SocketException;
public static native void setupRaSocket(FileDescriptor fd, int ifIndex) throws SocketException;

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: If406a4e507da916f5691d0ae4bded14dd168bc72