git: openjdk/jdk: 8265690: Use the latest Ubuntu base image version in Docker testing

[Aleksey Shipilev]

Changeset: b67b2b16
Author:    Aleksey Shipilev <shade at openjdk.org>
Date:      2021-04-27 16:36:15 +0000
URL:       https://git.openjdk.java.net/jdk/commit/b67b2b16

8265690: Use the latest Ubuntu base image version in Docker testing

Reviewed-by: sgehwolf, iignatyev, mseledtsov

! test/lib/jdk/test/lib/containers/docker/DockerfileConfig.java