/* SYSTEM_UI_FLAG_HIDE_NAVIGATION hides the navigation bars on the bottom or right of the screen.
** SYSTEM_UI_FLAG_FULLSCREEN hides the status bar across the top of the screen.
** SYSTEM_UI_FLAG_IMMERSIVE_STICKY makes the navigation and status bars ghosted overlays and automatically rehides them.
/* SYSTEM_UI_FLAG_HIDE_NAVIGATION hides the navigation bars on the bottom or right of the screen.
** SYSTEM_UI_FLAG_FULLSCREEN hides the status bar across the top of the screen.
** SYSTEM_UI_FLAG_IMMERSIVE_STICKY makes the navigation and status bars ghosted overlays and automatically rehides them.