Switch rake test to be run in our build-environment

[ScottSuarez]

Furthers allow us to make CI changes easily. I'm pointing rake test directly at the build environment in place of downstream-builder.

Release Note Template for Downstream PRs (will be copied)

[modular-magician]

Oops! It looks like you're using an unknown release-note type in your changelog entries:

• REPLACEME

Please only use the types listed in https://github.com/GoogleCloudPlatform/magic-modules/blob/master/.ci/RELEASE_NOTES_GUIDE.md.

[modular-magician]

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

Diff report

Your PR hasn't generated any diffs, but I'll let you know if a future commit does.

[modular-magician]

Tests analytics

Total tests: 2930
Passed tests 2628
Skipped tests: 302
Affected tests: 0

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

[ScottSuarez]

@trodge Could you do a pass on this when you get a chance?
/gcbrun

[modular-magician]

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

Diff report

Your PR hasn't generated any diffs, but I'll let you know if a future commit does.