Unpin OpenJDK Version

This change un-pins the version of OpenJDK that the build uses.  This
version was originally pinned to _21 due to an incompatibility between
Groovy and OpenJDK 1.7.0_25.  Now that _40 is available and which
addresses this incompatibility, it is safe to use the latest available
version.

[#55382544]
Merge 55382544-openjdk-upgrade to master

[Completes #55382544]