MTK Android SwitchPreference（设置-智能辅助-导航栏-导航栏可隐藏）
1.界面布局文件
packages/apps/PrizeSettings/res/xml/navigation_bar_prize.xml
-------------------------------------------------------------------------------
2.加载布局文件
packages/apps/PrizeSettings/src/com/android/settings/NavigationBarSettings.java
3.初始化全局变量
frameworks/base/packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java
/**prize-add-The navigation bar can be hidden-by-zfc-start*/loadIntegerSetting(stmt,Settings.System.PRIZE_ALLOW_HIDING_NAVBAR,R.integer.def_prize_flash_status);/**prize-add-The navigation bar can be hidden-by-zfc-end*/
frameworks/base/packages/SettingsProvider/res/values/defaults.xml