[Android] [bug] sidebar can't be collapsed in full-screen mode
https://s3.amazonaws.com/zotero.org/images/forums/u10781283/g0zv4go6zjizxdusycwm.gif
As the gif shows, the sidebar can't be collapsed in the full-screen mode unless another tap to exit that mode, which is quite cumbersome. I think the sidebar icon should be shown in a different way to be accessible in both modes. Thanks.