Save attribute checkbox state (#8010) not working

[gerard33]

Checklist

• I have updated to the latest available Home Assistant version.
• I have cleared the cache of my browser.
• I have tried a different browser to see if it is related to my browser.

Describe the issue you are experiencing

Save attribute checkbox state (#8010 and part of frontend release 20210224.0) is not working.

As discussed with @KTibow I made an issue to investigate this further (#7537 (reply in thread)).

Describe the behavior you expected

Save whether or not the attribute checkbox is checked in localStorage. This can help if you have a lot of entities, so you don't have to wait forever to load the attributes.

Steps to reproduce the issue

1. Uncheck the checkbox and refresh the page. After the refresh the checkbox is ticked again.
2. Both in Vivaldi and Edge.

What version of Home Assistant Core has the issue?

2012.3.1

What was the last working version of Home Assistant Core?

n/a

In which browser are you experiencing the issue with?

Vivaldi, Edge

Which operating system are you using to run this browser?

Windows 10

State of relevant entities

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Problem-relevant frontend configuration

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Javascript errors shown in your browser console/inspector

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