移动端静音问题

[rockhentai]

🐛 Bug Report

在移动端点击音量按钮将视频静音后，再次点击该按钮没有任何反馈，也不能像pc端一样点击音量条来将音量回复

To Reproduce

知乎移动端线上的视频播放器都有这个问题
https://www.zhihu.com/question/339268473/answer/872126420

Expected behavior

当声音正常时点击音量按钮，视频静音；
再次点击音量按钮，声音正常

Link to repl or repo (highly encouraged)

https://www.zhihu.com/question/339268473/answer/872126420

Run npx envinfo --system --binaries --npmPackages griffith --markdown --clipboard

Paste the results here:

## System:
 - OS: macOS High Sierra 10.13.6
 - CPU: (4) x64 Intel(R) Core(TM) i5-7360U CPU @ 2.30GHz
 - Memory: 51.10 MB / 8.00 GB
 - Shell: 3.2.57 - /bin/bash
## Binaries:
 - Node: 13.8.0 - ~/.nvm/versions/node/v13.8.0/bin/node
 - Yarn: 1.19.1 - /usr/local/bin/yarn
 - npm: 6.13.6 - ~/.nvm/versions/node/v13.8.0/bin/npm
## npmPackages:
 - griffith: ^1.5.0 => 1.5.0