Preference/Setting issue when using the Redhat Java plugin

[safisa]

Bug Description:

Hi,
In latest Theia there is a regression in the preference/setting view when the Redhat Java plugin is installed, all the Java settings were shown under one main category under Extenions--> Java, but now all the java sub-categories are rendered under the Extenions parent, making it difficult to know that those categories belong to the Java extension.

Maybe this was caused after this PR: #13819

Steps to Reproduce:

1. install Redhat java plugin (1.33)
2. open setting
3. you will see many new categories under the Extensions category, instead of adding only one Java category as before.

Additional Information

• Operating System: Mac
• Theia Version: 1.52

[tsmaeder]

Invoking @msujew for comment.

[msujew]

Can reproduce, looking at it right now :)