Improve tests for GenerateAutolinkingNewArchitecturesFileTask (#45510)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/45510

This is just a quality of life improvement, where we test the C++ autolinking
code generation a bit more.

Changelog:
[Internal] [Changed] - Improve tests for GenerateAutolinkingNewArchitecturesFileTask

Reviewed By: blakef

Differential Revision: D59907847

fbshipit-source-id: e6367cc3b1c01700310437b73bc984e3666b3499