[JENKINS-64751] Quote "docker exec" env-vars on Windows

[TBBle]

Based on c97bf23 from #220 which quoted "docker run" env-vars, this addresses JENKINS-64751 and JENKINS-65933.

I have not included any tests, as my understanding from #215 is that we do not have test infrastructure that supports docker-execution tests on Windows, similarly to #220.

• Draft because:
  • I wanted initial CI results from Jenkins
  • I need to test this with the reproduction case in the comments of JENKINS-64751
  • I need to get local sign-off due to employer requirements.

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[TBBle]

Hmm. I just noticed #244, which might block testing of this on the mainline. We're on 1.26 locally, so I'll either wait for #244 to land and rebase, or test it locally with a build of this change cherry-picked onto 1.26.

[TBBle]

Hmm. Both this and #244 hit an hour timeout in the CI system, and nothing's been built since six days ago, or merged into mainline since December, when it wasn't having that issue. So I suspect something's borked on the CI infrastructure side.

[TBBle]

#244's latest run wasn't so slow, so I guess the CI problem has been resolved. I'm not sure how to trigger a rerun, so I'll wait to see if local testing reveals any changes, and otherwise wait for #244 or similar to land, and rebase on that to trigger a CI run.

[TBBle]

Local test using mvn hpi:run and the same Windows node where I was able to produce failure before passed the same test. So I'm happy that this fix is correct, and will be trying to deploy it locally (cherry-picked onto 1.26) to get ourselves out from under this bug.