cloudrun_service: add anchors to regexes to resolve security errors

[BBBmau]

Resolves a security alert that was found from the recent security scan on both google and beta repos

• https://github.com/hashicorp/terraform-provider-google/security/code-scanning/896

Release Note Template for Downstream PRs (will be copied)

See Write release notes for guidance.

[modular-magician]

Hi there, I'm the Modular magician. I've detected the following information about your changes for commit 5e32e45:

Diff report

Your PR generated the following diffs in downstream repositories:

Repository	Diff Link	Changes
google provider	View Diff	1 file changed, 3 insertions(+), 3 deletions(-)
google-beta provider	View Diff	1 file changed, 3 insertions(+), 3 deletions(-)
terraform-google-conversion	View Diff	1 file changed, 3 insertions(+), 3 deletions(-)

Test report

Analytics

Total Tests	Passed	Skipped	Affected
39	31	8	0

Affected Service Packages

• cloudrun

Learn how VCR tests work

---

Step 1: Replaying Mode

🟢 All tests passed in Replaying mode! No Recording was needed.

View the replaying VCR build log

@BBBmau, @Capstan, @ian-mi VCR tests complete for 5e32e45!