chore: update ci to build in parallel by default

[aajtodd]

Issue #

N/A

Description of changes

• Run the CI build task in parallel
• Upgrade to actual 7.2 release of Gradle (from 7.2-rc-2)
• Define a new builder variant for testing that all services compile and test (from codebuild)
  • NOTE: The codebuild job is not marked as a required check. Let's see how it runs for a while and if it's stable before marking it required. It currently fails in all other branches due to the missing variant definition new to this branch.

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