[BUG]: `TransformAndroidManifest` can compute negative version codes

[BenHenning]

Describe the bug

When trying to build a release locally recently, I ran into a situation where my AAB ended up being assembled with negative version codes (per #6265).

Steps To Reproduce

1. Check out a shallow copy of Oppia Android.
2. Try to build a release.
3. Use bundletool to observe the version codes.
4. Observe negative version codes.

Expected Behavior

Version codes should never be negative. In this case it's unavoidable since a shallow copy of the repository will have the wrong commit count on develop, however we should just have TransformAndroidManifest outright fail in these cases.

Screenshots/Videos

No response

What device/emulator are you using?

No response

Which Android version is your device/emulator running?

No response

Which version of the Oppia Android app are you using?

No response

Additional Context

No response

[thirumani-vihaan]

I think failing the build early makes a lot of sense here rather than letting a bad AAB generate silently. Since TransformAndroidManifest runs via Bazel, I was thinking we could just check if the computed version code drops below 0 and throw an IllegalStateException. We could also add a helpful error message suggesting they run git fetch --unshallow to fix their clone history. Do you think that’s the right approach? If so, I’d love to take this issue on and put up a PR.

[Neer-rn]

Thanks @thirumani-vihaan!! yes, this approach sounds correct to me. Please do add a regression test in your PR that verifies the transform fails with a clear, actionable error when the computed version code is negative. Assigning this issue to you.

[thirumani-vihaan]

Hey @Neer-rn, opened PR #6317. Added the check(versionCode > 0) constraint we discussed and the regression test for the shallow clone math.

I also signed the CLA.. PTAL whenever you have a chance. Thanks!