fix(google-cloud-secretmanager): improve librarian.js script and add missing functions

[quirogas]

During the previous autogeneration run (commit ea7ec63 ), the generator updated its output format to include trailing commas in path template declarations. This formatting change caused the regex in librarian.js to fail silently when trying to match and replace the templates, leaving the v1 client with missing properties and causing runtime crashes when accessing version path helpers. This PR updates librarian.js with a regex that matches both formatting styles and adds verification checks that throw an error and set a non-zero exit code if any replacement fails, preventing silent failures in future generation runs.

[gemini-code-assist]

Code Review

This pull request updates the librarian.js script to process multiple client files and throw an error if replacements fail, while also adding path templates and helper methods to the v1 and v1beta2 Secret Manager service clients. Feedback was provided to make the librarian.js script idempotent to prevent build pipeline failures when run on already-processed files.

[gemini-code-assist]

The replaceInFile function now throws an error if no replacement is made. Since librarian.js is run as a post-processing script, running it on already-processed files (or running it twice) will cause the script to fail with an error, breaking the build/generation pipeline.

To make the script idempotent and safe to run multiple times, we can check if the file has already been processed (e.g., by checking if it contains secretVersionPath) and skip it gracefully.

Suggested change

	filePaths.forEach(filePath => {
	if (fs.existsSync(filePath)) {
	replaceInFile(filePath, /return\sPromise\.resolve\(\);\s+}\s+}/g, replacement1);
	replaceInFile(filePath, /topicPathTemplate:\s+new\s+this\._gaxModule\.PathTemplate\(\s+'projects\/{project}\/topics\/{topic}',?\s*\),?\s*};/g, replacement2);
	}
	});
	filePaths.forEach(filePath => {
	if (fs.existsSync(filePath)) {
	const content = fs.readFileSync(filePath, 'utf8');
	if (content.includes('secretVersionPath')) {
	console.log("File " + filePath + " is already processed. Skipping.");
	return;
	}
	replaceInFile(filePath, /return\sPromise\.resolve\(\);\s+}\s+}/g, replacement1);
	replaceInFile(filePath, /topicPathTemplate:\s+new\s+this\._gaxModule\.PathTemplate\(\s+'projects\/{project}\/topics\/{topic}',?\s*\),?\s*};/g, replacement2);
	}
	});

[quirogas]

@pearigee What do you think? Our long-term goal is to remove the file. Since this will eventually run in Librarian, we should add error handling in librarian for cases where the file fails rather than making it idempotent.