遲遲等不到官方的更新通知，就自己下載ota檔sideload update了
Android O brings picture-in-picture support so you can watch YouTube while
hailing a Lyft 這篇文中（https://goo.gl/21QGc1）有提到：
“Picture-in-picture is just one of the handful of new features that come with
Android O today. Compatible devices for the preview include the Nexus 5X,
Nexus 6P, Nexus Player, Pixel, Pixel XL, and Pixel C.”
在設定裡頭也有確定picture in picture有開啟
https://imgur.com/joNzbEh
開了兩個app來測試（hangouts, youtube）
想試驗邊用hangouts邊用picture in picture 看youtube的情景
在切換的視窗沒看到東西
https://imgur.com/KMoFNXE
在Youtube的視窗也是
https://imgur.com/6qgHs1B
試過單點、雙點recent, home, back 都失敗
有人有用nexus 5x 試成功嗎？