Add explicit dependencies so that google_composer_environment is created after IAM resources in acceptance test

[SarahFrench]

Relates to (might fix...) hashicorp/terraform-provider-google#15091

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

[modular-magician]

Tests analytics

Total tests: 3275
Passed tests 2941
Skipped tests: 334
Affected tests: 0

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

[zli82016]

This PR changes the test TestAccComposerEnvironment_fixPyPiPackages, but this test always passed. I wonder if I miss something.

https://hashicorp.teamcity.com/test/-7930500571679198696?currentProjectId=TerraformProviders_GoogleBeta_NightlyTests&expandTestHistoryChartSection=true

[SarahFrench]

@zli82016 you're not missing anything - the last couple of weeks Ive looked at test failures related to missing permissions, and during that work I found that this dependency was missing. This PR started from finding a problem with a tests config instead of starting with a failing test. I linked it to the issue in the PR description because I assumed it was related, but it's not.

[zli82016]

LGTM. Thanks for the information.