Update iOS flutterEngine libraryURI

[johypark]

Description of what this PR is changing or adding, and why:
I have to import another file in main and use package prefix in libraryURI
reference
Issues fixed by this PR (if any):

PRs or commits this PR depends on (if any):

Presubmit checklist

• This PR is marked as draft with an explanation if not meant to land until a future stable release.
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• This PR follows the Google Developer Documentation Style Guidelines — for example, it doesn’t use i.e. or e.g., and it avoids I and we (first person).
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[jmagman]

@gaaclarke is this right? The libraryURI should be package:your_package_name/other_file.dart?

flutter/engine#30726

[gaaclarke]

This sounds like advice that will not apply to everyone. So at a bare minimum it should be an added note instead of modifying the prevailing guidance.

In order to change the guidance I'd like to see a bug issued. In order to add the note I'd like to see an example project that demonstrates it's correctness.

[sfshaza2]

/gcbrun

[flutter-website-bot]

Visit the preview URL for this PR (updated for commit 117aa72):

https://flutter-docs-prod--pr11205-patch-1-yqv1floz.web.app

[sfshaza2]

@johypark, would you mind opening a bug against the flutter s/w repo for this? (As per @gaaclarke.)

[sfshaza2]

Failing Greg's requests, I'm closing this PR.