chore(messaging, android): fix native documentation

[Lyokone]

Description

This class isn't used anymore and the documentation is outdated. Removing.

Related Issues

closes #12936

Checklist

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• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• My PR includes unit or integration tests for all changed/updated/fixed behaviors (See Contributor Guide).
• All existing and new tests are passing.
• I updated/added relevant documentation (doc comments with ///).
• The analyzer (melos run analyze) does not report any problems on my PR.
• I read and followed the Flutter Style Guide.
• I signed the CLA.
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Breaking Change

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• Yes, this is a breaking change.
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