[jdk11u-dev] RFR: 8294740: Add cgroups keyword to TestDockerBasic.java

[Severin Gehwolf]

Clean backport. Test only follow-up fix of #1526.

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Depends on: https://git.openjdk.org/jdk11u-dev/pull/1526

Commit messages:
 - 8294740: Add cgroups keyword to TestDockerBasic.java

Changes: https://git.openjdk.org/jdk11u-dev/pull/1527/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=1527&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8294740
  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/1527.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev pull/1527/head:pull/1527

PR: https://git.openjdk.org/jdk11u-dev/pull/1527