Add missing attribute reference and closing bracket to TestAccVmwareenginePrivateCloud_vmwareEnginePrivateCloudUpdate test

[SarahFrench]

Closes hashicorp/terraform-provider-google#16718

Release Note Template for Downstream PRs (will be copied)

[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.

Terraform GA: Diff ( 1 file changed, 2 insertions(+), 2 deletions(-))
Terraform Beta: Diff ( 1 file changed, 2 insertions(+), 2 deletions(-))

[modular-magician]

Tests analytics

Total tests: 3269
Passed tests 2935
Skipped tests: 334
Affected tests: 0

$\textcolor{green}{\textsf{All tests passed in REPLAYING mode.}}$
View the build log

[SarahFrench]

I've triggered the affected test here in TeamCity