fix(37364): No completions in string literal index on mapped type

[a-tarasyuk]

Fixes #37364

[elibarzilay]

(I made a minor change, leaving the original expression function instead of the return thing.)

[a-tarasyuk]

@elibarzilay Thanks for your changes 👍, you are right the return statement was useless., I'm not sure that new changes for ternary operator have the right indentation., it seems that condition has been formatted without addition indentation. Some time ago I was working on migration the repo to the eslint and as I remember correctly, the following formatting was not acceptable for eslint/indent before we disabled it due to performance reasons. Can @uniqueiniquity you check?, maybe I'm wrong.

expression
? true
: false

Is it acceptable to do like so?

 symbols: type.getApparentProperties().filter(prop =>
     !isPrivateIdentifierPropertyDeclaration(isTransientSymbol(prop) && prop.syntheticOrigin ? prop.syntheticOrigin.valueDeclaration : prop.valueDeclaration)),

or

symbols: type.getApparentProperties().filter(prop =>
    !isPrivateIdentifierPropertyDeclaration(
        isTransientSymbol(prop) && prop.syntheticOrigin ? prop.syntheticOrigin.valueDeclaration : prop.valueDeclaration)),

cc @andrewbranch

[elibarzilay]

(@a-tarasyuk, it's used elsewhere too, but in any case I just wanted to shorten the line...)