Merge "Camera: Address device state listener delay" into udc-qpr-dev

import java.util.Arrays;

import java.util.Comparator;

import java.util.HashMap;

import java.util.Iterator;

import java.util.Map;

import java.util.Set;

import java.util.concurrent.Executor;

            boolean folded = ArrayUtils.contains(mFoldedDeviceStates, state);

            mFoldedDeviceState = folded;

            ArrayList<WeakReference<DeviceStateListener>> invalidListeners = new ArrayList<>();

            for (WeakReference<DeviceStateListener> listener : mDeviceStateListeners) {

                DeviceStateListener callback = listener.get();

            Iterator<WeakReference<DeviceStateListener>> it = mDeviceStateListeners.iterator();

            while(it.hasNext()) {

                DeviceStateListener callback = it.next().get();

                if (callback != null) {

                    callback.onDeviceStateChanged(folded);

                } else {

                    invalidListeners.add(listener);

                    it.remove();

                }

            }

            if (!invalidListeners.isEmpty()) {

                mDeviceStateListeners.removeAll(invalidListeners);

            }

        }

        public synchronized void addDeviceStateListener(DeviceStateListener listener) {

            listener.onDeviceStateChanged(mFoldedDeviceState);

            mDeviceStateListeners.removeIf(l -> l.get() == null);

            mDeviceStateListeners.add(new WeakReference<>(listener));

        }