Fix release build by updating icon reference

[XiangRongLin]

Was changed in DayNight Theme, but only in debug resource and not release resource.

What is it?

• Bugfix (user facing)
• Feature (user facing)
• Codebase improvement (dev facing)
• Meta improvement to the project (dev facing)

Description of the changes in your PR

• Caused by Migrate to Android DayNight Theme, fix Light Theme, minor UI improvements #5927
• gradle assempleRelease now works again

Notes

• For the future this means that reviewers need to look out for changes in build flavor specific files and make sure that they are made in all flavours (debug and release). But even if it is missed, it will be caught by my nightly builds.
• https://github.com/XiangRongLin/NewPipe-nightly/runs/2261992423?check_suite_focus=true

Due diligence

• I read the contribution guidelines.