[jdk11u-dev] RFR: 8255787: Tag container tests that use cGroups with cgroups keyword

[Goetz Lindenmaier]

Backport to have the same keywords in 11 and 17ff.
I had to resolve one TEST.ROOT because there are more keywords in 11. Trivial.

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Commit messages:
 - Backport 4df8abc200568f09ac714437397dbc7f521015cf

Changes: https://git.openjdk.java.net/jdk11u-dev/pull/1075/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=1075&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8255787
  Stats: 20 lines in 15 files changed: 15 ins; 0 del; 5 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/1075.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/1075/head:pull/1075

PR: https://git.openjdk.java.net/jdk11u-dev/pull/1075