[extension/googlecloudlogentryencoding] Fix incorrect snake_case conversion for numeronyms (e.g. k8s)

[57Ajay]

Description:

This PR fixes an issue where the googlecloudlogentryencoding extension incorrectly converted log field names containing numeronyms (abbreviations containing numbers, such as "k8s") into snake_case.

The Problem:

The previous implementation relied on strcase.ToSnakeWithIgnore, which treats a digit followed by a lowercase letter as a word boundary.

• Input: labels.authorization.k8s.io/decision
• Previous Output: labels.authorization.k8_s.io/decision (Incorrect split at 8 and s)
• Expected Output: labels.authorization.k8s.io/decision

The Solution:

Introduced a shared.ToSnakeCase helper function that wraps the existing library call. It uses a regex replacement ((\d)_([a-z]) -> ${1}${2}) to post-process the string, re-merging digits and subsequent lowercase letters. This approach preserves standard numeronyms (e.g., k8s, v1beta) while maintaining snake_case for standard camelCase inputs.

Link to tracking Issue:

Fixes #46571

Testing:

• Added unit tests in internal/shared to cover edge cases (k8s, v1beta, standard camelCase).
• Updated log_entry_test.go to verify the fix in the extension logic.
• Updated golden files (activity_expected.yaml) to reflect the correct output.
• Ran tests locally; all tests passed.

Documentation:

• I have updated the changelog (.chloggen directory)

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[constanca-m]

Thank you

[57Ajay]

Thank you

Should i add this:

func ToSnakeCase(s, ignore string) string {
	result := strcase.ToSnakeWithIgnore(s, ignore)

	// Fast path: if there are no digits, skip the regex entirely
	if !strings.ContainsAny(result, "0123456789") {
		return result
	}

	return digitToLetter.ReplaceAllString(result, "${1}${2}")
}

so we skip the regex entirely if no numbers

[paulojmdias]

/workflow-approve

[paulojmdias]

/workflow-approve

[57Ajay]

@paulojmdias It looks like the Checkout Repo step is hitting a GitHub 500 error across multiple jobs (11 failures). Could you please re-run the failed checks?

[paulojmdias]

@57Ajay You could ask for a rerun commenting /rerun only

[57Ajay]

/rerun

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