Back out "Add png extension only if file exist when load local image" (#47417)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/47417

Backing out this change as it was breaking an internal app. I'll reland this next week when I have more time.

## Changelog:
[iOS][Changed] - Revert fix that checks whether an image is present on disk.

## Facebook:
This is breaking twilight.

Differential Revision: D65479912

fbshipit-source-id: dcd5ac5f3d98ba2f10b9519f09d3eb1fd454da61