Bumping the warn agp version from 7.3 (sept 2022) to 8.3 (feb 2024).
This is because we will likely need to depend on apis available in the
newer versions of AGP as part of our work to migrate to the
public/stable agp api. Warning will not break customers but starts the
clock on being able to bump error version.
I would have also bumped the error version but want to get this in
before the 3.32 cut next monday and adding errors can cause review
delay.
## Pre-launch Checklist
- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [ ] I listed at least one issue that this PR fixes in the description
above.
- [ ] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.
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Co-authored-by: Jackson Gardner <jacksongardner@google.com>