Fluentui: Background color removed on ChoiceGroup when disabled

[Puyush6889]

https://github.com/microsoft/fluentui/blob/492fff101f5943affeae637bebe761fdd163b0a0/packages/office-ui-fabric-react/src/components/ChoiceGroup/ChoiceGroupOption/ChoiceGroupOption.styles.ts#L178

Why was the background color removed on raidobutton when it's disabled. Our team is using fabric version 7.7.0.

[aneeshack4]

@Puyush6889 If you look at "git blame" you can see that it was removed in this PR: https://github.com/microsoft/fluentui/commit/c83add9cbc62c6530f2a9afd06fad57297473b40 by @Vitalius1 - looks like it was removed among bulk style adjustments a year ago - the PR description doesn't say anything else but maybe Vitalie can provide further context.

[Vitalius1]

This was a part of the fluentization process for the Fabric 7 so this was definitely an intentional change. A quick look at the line that was linked the change was to follow the design specs for fluent looks of the control (when a choice is checked but at the same time is disabled). Below are some screenshots to how it was before (Fabric 6 MDL2 styling) and after (Fabric 7 fluent styling)

Before

# After

[Puyush6889]

In fabric 6 the the disabled and checked state was treated to be same. So when a checkbox was disabled it would be marked out gray.

After syncing with @Vitalius1, fabric 7 they keep track of the state so when it's disabled the circle is changed to disabled state as shown in the picture