Android 6.0 隐藏导航栏 和 状态栏

frameworks\base\core\res\res\values\dimens.xml

   <!-- Height of the status bar -->
mm    <dimen name="status_bar_height">0dp</dimen>
    <!-- Height of the bottom navigation / system bar. -->
mm    <dimen name="navigation_bar_height">0dp</dimen>
    <!-- Height of the bottom navigation bar in portrait; often the same as @dimen/navigation_bar_height -->
mm    <dimen name="navigation_bar_height_landscape">0dp</dimen>