fix(java): tidy default released version

[noahdietz]

Tidy the java.released_version if it was set to the default of 0.0.0.

Noticed this being serialized while testing a diff change.

[gemini-code-assist]

Code Review

This pull request adds logic to clear the ReleasedVersion of a Java library if it matches a defaultReleasedVersion, and includes a unit test for this behavior. However, a review comment correctly points out that defaultReleasedVersion is undefined in the package, which will lead to a compilation error.

[gemini-code-assist]

The variable defaultReleasedVersion is used here, but it is not defined anywhere in the java package or in internal/librarian/java/defaults.go. This will cause a compile-time error. Please define defaultReleasedVersion as a constant (e.g., "0.0.0") in this package.

[zhumin8]

I think this better be part of add.
Based on the example, IIUC you are adding a new API path (google/cloud/kms/v2) to an existing library.
So I expect librarian add google/cloud/kms/v2 not changing released_version of the library. Note that the original config has released_version omitted because it can be derived from version: 2.97.0-SNAPSHOT, it should bereleased_version: 2.96.0 . released_version: 0.0.0 is not a right config.
Removing this via tidy is saying this is a valid config, only has redundant info.

[noahdietz]

I think this better be part of add. Based on the example, IIUC you are adding a new API path (google/cloud/kms/v2) to an existing library. So I expect librarian add google/cloud/kms/v2 not changing released_version of the library. Note that the original config has released_version omitted because it can be derived from version: 2.97.0-SNAPSHOT, it should bereleased_version: 2.96.0 . released_version: 0.0.0 is not a right config. Removing this via tidy is saying this is a valid config, only has redundant info.

Thanks and your comment on the versions.txt PR clarified my confusion. Good catch. Closing this PR.