Media FullScreen but the icon is not correct

[hxwhou]

Please fill out the following template so we can reproduce and fix your issue as quickly as possible!

Environment:

• Preview version: 1.12.0
• Browser name and version: Chrome
• Operating system and version: Mac OS X EI

Steps to reproduce the problem:

1. Open a video to preview
   2.Enter FullScreen
   3.The class 'bp-enter-fullscreen-icon' should be change to 'bp-exit-fullscreen-icon'

What is the expected behavior? (Screenshots can be helpful here)
the icon should be change to 'bp-exit-fullscreen-icon'

What went wrong? (Screenshots can be helpful here)
Link to application or sample code:

If relevant, link to file (or attach file here):

[jeremypress]

Thanks for submitting @hxwhou, I've successfully reproduced this and we'll address it in a future release.

[jeremypress]

Fixed with #456