Fix ConcurrentModificationException in GattService.onScanResult

import com.android.internal.app.IBatteryStats;

import java.util.ArrayDeque;

import java.util.Collections;

import java.util.Deque;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Map;

import java.util.Set;

import java.util.concurrent.ConcurrentHashMap;

import java.util.concurrent.CountDownLatch;

import java.util.concurrent.TimeUnit;

    private CountDownLatch mLatch;

    ScanManager(GattService service) {

        mRegularScanClients = new HashSet<ScanClient>();

        mBatchClients = new HashSet<ScanClient>();

        mRegularScanClients = Collections.newSetFromMap(new ConcurrentHashMap<ScanClient, Boolean>());

        mBatchClients = Collections.newSetFromMap(new ConcurrentHashMap<ScanClient, Boolean>());

        mService = service;

        mScanNative = new ScanNative();

        curUsedTrackableAdvertisements = 0;