修改48dp为0dp，底部的导航栏，状态栏被隐藏
修改文件：px30_android8.1/frameworks/base/core/res/res/values/dimens.xml
<!--状态栏--><dimen name="status_bar_height">48dp</dimen><!-- Height of the bottom navigation / system bar. --><!--导航栏--><dimen name="navigation_bar_height">48dp</dimen><!-- Height of the bottom navigation bar in portrait; often the same as @dimen/navigation_bar_height --><dimen name="navigation_bar_height_landscape">48dp</dimen>