Android OnDeviceAppPrediction 优化

最近在Android R的一个项目上，Google 在基于Launcher3的基础上，集成了一个OnDeviceAppPrediction服务。功能呢，就是在All App View界面上端显示常用的应用和近期使用的应用。在所接触的项目中，经测试同事的辛苦挖掘，找出了不少问题：

1.Google对出现在近期列表中的应用执行卸载操作后做一个填充列表的动作，导致列表出现空缺。

2.使用其他应用后，没有实时改刷新界面显示。

一下便是我针对这两个问题的做的优化：

1.卸载应用后，做填充

/*
 * Copyright (C) 2019 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.android.apppredictionservice;

import android.app.prediction.AppPredictionContext;
import android.app.prediction.AppPredictionSessionId;
import android.app.prediction.AppTarget;
import android.app.prediction.AppTargetEvent;
import android.app.prediction.AppTargetId;
import android.content.BroadcastReceiver;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.SharedPreferences;
import android.content.pm.ApplicationInfo;
import android.content.pm.LauncherActivityInfo;
import android.content.pm.LauncherApps;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.os.CancellationSignal;
import android.service.appprediction.AppPredictionService;
import android.util.Log;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.function.Consumer;

import static android.os.Process.myUserHandle;
import static android.text.TextUtils.isEmpty;
import static java.util.Collections.emptyList;
/*
 * New plugin that replaces prediction driven Aiai APK in P
 * PredictionService simply populates the top row of the app
 * drawer with the 5 most recently used apps. Each time a new
 * app is launched, it is added to the left of the top row.
 * Duplicates are not added.
 */
public class PredictionService extends AppPredictionService {

    public static final String MY_PREF = "mypref";

    private static final String TAG = PredictionService.class.getSimpleName();

    private static final int MAX_NUM = 5;
    private static final String[] DEFAULT_PACKAGES = new String[]{
            "com.google.android.apps.photos",   // Photos
            "com.google.android.apps.maps",     // Maps
            "com.google.android.gm",            // Gmail
            "com.android.settings",          // Settings
            "com.google.android.calculator" //Calculator
    };
    private final Set<AppPredictionSessionId> activeLauncherSessions = new HashSet<>();
    private final List<AppTarget> predictionList = new ArrayList<>(5);

    private final List<String> appNames = new ArrayList<>(5);
    private final String[] appNameKeys = new String[] {
            "first", "second", "third", "fourth", "fifth" };
    SharedPreferences sharedPreferences;
    SharedPreferences.Editor editor;

    private PackageRemovedBroadcastReceiver mPackageRemovedBroadcastReceiver;
    private String mMostRecentComponent;
    private AppTarget mAppTarget;

    private String mPackageName;
    private Context mContext;
    private boolean mRemovedLast = true;
    private boolean mDebug = false;
    private boolean mAppSuggestionsEnabled = true;