Update template to gitignore `android/app/.cxx` (#34430)
Update template to gitignore `android/app/.cxx` (#34430)

Summary:
CMake gens running debug
- `android/app/.cxx/Debug/*`
- `android/app/.cxx/RelWithDebInfo/*`

Neither/nothing during release.

So probably want the 87 debug files untracked.

Follow-up: https://github.com/facebook/react-native/pull/34354

_macOS 13b, RN 0.70.0-rc.3_

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[Android] [Added] - Update template to gitignore `android/app/.cxx`

Pull Request resolved: https://github.com/facebook/react-native/pull/34430

Test Plan: Everything builds and runs as expected

Reviewed By: cipolleschi

Differential Revision: D38752097

Pulled By: cortinico

fbshipit-source-id: 61c31317d5e45f831445841f3e14da871b3903e5

facebook/react-native,janicduplessis/react-native,javache/react-native,janicduplessis/react-native,javache/react-native,javache/react-native,facebook/react-native,janicduplessis/react-native,janicduplessis/react-native,facebook/react-native,janicduplessis/react-native,janicduplessis/react-native,javache/react-native,janicduplessis/react-native,facebook/react-native,facebook/react-native,facebook/react-native,javache/react-native,javache/react-native,javache/react-native,facebook/react-native,facebook/react-native,janicduplessis/react-native,javache/react-native,facebook/react-native,javache/react-native