Convert ConfigUtils to Kotlin

[madhurgupta10]

Summary:
As per the discussion from the thread.

Convert ConfigUtils.java to Kotlin.

Want to work on this issue?
Yes

[neslihanturan]

Hey @madhurgupta10 , thanks a lot for your issue and PR! But we usually discuss the issue beforehand. Do we want to convert our util files to kotlin, everyone?

[macgills]

Yes, that was end of the discussion on #747 I believe

[madhurgupta10]

@neslihanturan It was discussed already so I created my PR. Sorry I forgot to link the parent issue :)

[misaochan]

Yes, any kotlin conversions that adhere to our code quality guidelines are welcome. :)

[neslihanturan]

Oh sorry I missed we let it be used in any files, thanks for clarification :)