Cannot search default sources

Copy https://bugzilla.redhat.com/show_bug.cgi?id=1879106

Description of problem: The search option in "add input source" is not working properly.

Version-Release number of selected component (if applicable): Fedora-33

Steps to Reproduce:

1. Go to the settings --> region and language -- > input sources
2. Go to add input source(+)
3. try to search(:) some language specific input source. For example hangul(Korean), Intelligent pinyin(Chinese) , typing booster, Cangjie(chinese hong kong)

Actual results:

1. Search will work for some input sources like typing booster( it will give "other") but it does not work for some input like hangul. intelligent pinyin, cangjie etc

Expected results:

1. The search should give proper results for all.