mute are duplicated and in the wrong position in pip mode

[Bulogan]

Sanity checks (must complete)

• I have read and followed the installation instructions in the README
• I have not modified the userChrome.css file
• I have tested the latest release for my Firefox version, or commit on master/beta branch (beta is for Firefox Beta only)

Describe the bug
mute button are duplicated and in the wrong position in picture in picture mode.

To Reproduce
Steps to reproduce the behavior:

1. Go in to pip mode
2. notice the mute button becomes two

Screenshots

System info

• OS: [e.g. Windows 10]
• Firefox version: [e.g. 87]