[camerax] Fix CameraInfo cast causing failure in integration test

[camsim99]

Fixes a cast causing a post-submit failure for the Flutter roll into packages: https://github.com/flutter/packages/runs/12290760669.

Pre-launch Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I read the Tree Hygiene wiki page, which explains my responsibilities.
• I read and followed the relevant style guides and ran the auto-formatter. (Unlike the flutter/flutter repo, the flutter/packages repo does use dart format.)
• I signed the CLA.
• The title of the PR starts with the name of the package surrounded by square brackets, e.g. [shared_preferences]
• I listed at least one issue that this PR fixes in the description above.
• I updated pubspec.yaml with an appropriate new version according to the pub versioning philosophy, or this PR is exempt from version changes.
• I updated CHANGELOG.md to add a description of the change, following repository CHANGELOG style.
• I updated/added relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or this PR is test-exempt.
• All existing and new tests are passing.

[flutter-dashboard]

It looks like this pull request may not have tests. Please make sure to add tests before merging. If you need an exemption to this rule, contact Hixie on the #hackers channel in Chat (don't just cc him here, he won't see it! He's on Discord!).

If you are not sure if you need tests, consider this rule of thumb: the purpose of a test is to make sure someone doesn't accidentally revert the fix. Ask yourself, is there anything in your PR that you feel it is important we not accidentally revert back to how it was before your fix?

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[stuartmorgan-g]

LGTM.

Do we know how a roll broke this?

[camsim99]

Do we know how a roll broke this?

I'm actually confused about this, but this test started breaking for me late last week after making no changes to anything related (except maybe run the test with the master Flutter branch, which I'm guessing may be the common thread). The integration test also passes on one device, but not the other. Because of that, my guess is that it's something with Dart but I'm not sure if that makes sense...

[camsim99]

Also, @stuartmorgan is this going to be able to land or will submit-queue block it?

[stuartmorgan-g]

The warning: land on red to fix tree breakage label will allow autosubmit to land into a red tree, for cases like this one.