Decompress files for aaa_update_test

Ok the only reference to this archive file is here:

    // Check to ensure an existing module can't be reinstalled. Also checks that
    // the archive was extracted since we can't know if the module is already
    // installed until after extraction.
    $validArchiveFile = __DIR__ . '/../../aaa_update_test.tar.gz';
    $edit = [
      'files[project_upload]' => $validArchiveFile,
    ];

I think we can just extract it and compress it right before this step as part of the step. It creates a bit of churn on each test, but it does solve the immediate security concern.

There are a lot of references in the code to modules/update/tests/aaa_update_test.module, that file does not exist though so I'm not sure if there is a process I'm missing that extracts the archive first.