Revert "Another attempt to fix vpython in Cloud Build."

This reverts commit e7bc0844989faff96aa22ae052cc8603d6f8c6b9.

Reason for revert: Broke fiddle.

Original change's description:
> Another attempt to fix vpython in Cloud Build.
> 
> I think the underlying issue is switching to the 'skia' user
> to do the build. Instead let's try building as root and then
> chown the generated files which are then used by subsequent
> Dockerfiles.
> 
> Bug:993053
> Change-Id: I314a6c83f70e611ec0fafe93ae136d218d153cfb
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/247107
> Reviewed-by: Joe Gregorio <jcgregorio@google.com>
> Commit-Queue: Joe Gregorio <jcgregorio@google.com>

TBR=borenet@google.com,jcgregorio@google.com

Change-Id: I2e0968bc032a2c7716d95d51ba598d94fc67f1ca
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 993053
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/247143
Reviewed-by: Joe Gregorio <jcgregorio@google.com>
Commit-Queue: Joe Gregorio <jcgregorio@google.com>
1 file changed