Make type assertions more defensive on the secret manager datasources

[abheda-crest]

Refactor the Secret Manager datasources based on the comments received on the PR #11754:

1. Make type assertions more defensive based on the comment
2. Make the error messages returned from the function not capitalized based on the comment
3. Added extra check to confirm if the response has the critical field like name based on the comment

Release Note Template for Downstream PRs (will be copied)

[github-actions]

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@NickElliot, a repository maintainer, has been assigned to review your changes. If you have not received review feedback within 2 business days, please leave a comment on this PR asking them to take a look.

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[modular-magician]

Hi there, I'm the Modular magician. I've detected the following information about your changes:

Diff report

Your PR generated some diffs in downstreams - here they are.

google provider: Diff ( 4 files changed, 96 insertions(+), 57 deletions(-))
google-beta provider: Diff ( 4 files changed, 96 insertions(+), 57 deletions(-))

[modular-magician]

Tests analytics

Total tests: 84
Passed tests: 80
Skipped tests: 4
Affected tests: 0

Click here to see the affected service packages

• secretmanager
• secretmanagerregional

🟢 All tests passed!

View the build log

[abheda-crest]

@NickElliot Could you please review this PR?

[github-actions]

@NickElliot This PR has been waiting for review for 3 weekdays. Please take a look! Use the label disable-review-reminders to disable these notifications.

[modular-magician]

Hi there, I'm the Modular magician. I've detected the following information about your changes:

Diff report

Your PR generated some diffs in downstreams - here they are.

google provider: Diff ( 4 files changed, 96 insertions(+), 57 deletions(-))
google-beta provider: Diff ( 4 files changed, 96 insertions(+), 57 deletions(-))

[modular-magician]

Tests analytics

Total tests: 84
Passed tests: 80
Skipped tests: 4
Affected tests: 0

Click here to see the affected service packages

• secretmanager
• secretmanagerregional

🟢 All tests passed!

View the build log

[github-actions]

@GoogleCloudPlatform/terraform-team @NickElliot This PR has been waiting for review for 1 week. Please take a look! Use the label disable-review-reminders to disable these notifications.

[NickElliot]

sorry for the delay, but the changes LGTM! @trodge does this look like it aligns with what you were suggesting in the previous PR?

[github-actions]

This PR is approved and has been waiting for merge for 1 week. Is it ready to merge? Use the label disable-review-reminders to disable these notifications.

[github-actions]

@NickElliot This PR is approved and has been waiting for merge for 2 weeks. Is it ready to merge? Use the label disable-review-reminders to disable these notifications.

[abheda-crest]

Hi @trodge, @NickElliot has approved the PR. Could you please take a final look? Thank you!

[github-actions]

@NickElliot This PR has been waiting for review for 3 weekdays. Please take a look! Use the label disable-review-reminders to disable these notifications.