code: private void setImmersiveSticky() {
          mActivity.getWindow().getDecorView().setSystemUiVisibility(
                  View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                          | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                          | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                          | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                          | View.SYSTEM_UI_FLAG_FULLSCREEN
                          | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);
      }
docs: https://developer.android.com/training/system-ui/immersive.html