网上有一种方法说是修改frameworks/base/core/res/res/values/config.xml中的

<!-- Controls the navigation bar interaction mode:
         0: 3 button mode (back, home, overview buttons)
         1: 2 button mode (back, home buttons + swipe up for overview)
         2: gestures only for back, home and overview —>
<integer name="config_navBarInteractionMode”>2</integer>

但是似乎并没有起作用。经过后面研究发现不是修改这个配置文件，而是要去修改相应芯片下面的配置文件（我的板卡芯片是rk3566）：device\rockchip\rk356x\overlay\frameworks\base\core\res\res\values\config.xml

    <!--  Maximum number of supported users -->
    <integer name="config_multiuserMaximumUsers">3</integer>
    <!-- Controls the navigation bar interaction mode:
         0: 3 button mode (back, home, overview buttons)
         1: 2 button mode (back, home buttons + swipe up for overview)
         2: gestures only for back, home and overview -->
    <integer name="config_navBarInteractionMode">2</integer>

重新编译烧录后，目的达成。