How to register a callback for keyguard state changes in Kotlin?

Question

I need to to register a callback to be invoked whenever the phone is locked/unlocked. This is the LockStateReceiver class which extends BroadcastReceiver:

public class LockStateReceiver extends BroadcastReceiver {

    public static boolean CURRENT_KEYGUARD_STATE = false;

    static {
        Context context = VectorApplication.Companion.getAppContext();
        KeyguardManager keyguardManager = (KeyguardManager) context.getSystemService(Context.KEYGUARD_SERVICE);
        CURRENT_KEYGUARD_STATE = keyguardManager.isKeyguardLocked();
    }

    @Override
    public void onReceive(final Context context, final Intent intent) {
        System.out.println(">>> keyguard state changed");
    }
}

Now I want to use this receiver:

val mLockStateReceiver = LockStateReceiver()
BroadcastManager.registerSystemReceiver(
    mLockStateReceiver,
    IntentFilter(Intent.ACTION_KEYGUARD_LOCKED),
    VectorApplication.getAppContext()
)

But there's no Intent.ACTION_KEYGUARD_LOCKED.