RFR: 8224502 & 8224506 Container testbugs

[Bob Vandette]

Please review these two Docker container test bugs that I’d like to get fixed in JDK13.
Misha has already reviewed and approved these fixes.

I’ve tested these changes by running all Docker container tests locally with a fastdebug build
and also under mach5.

BUG:
https://bugs.openjdk.java.net/browse/JDK-8224502
[TESTBUG] JDK docker test TestSystemMetrics.java fails with access issues and OOM

WEBREV:
http://cr.openjdk.java.net/~bobv/8224502/webrev.01

This problem is caused by the test consuming too much memory.  The author
expected to allocate a 64MB array but instead allocated 512MB.  I also
added a container memory limit of 256MB in order to ensure that if the host running
the test does not have sufficient memory, we’ll get a better handle on the 
cause of the failure.

--------------------------------------------------------------------------------------

BUG:
https://bugs.openjdk.java.net/browse/JDK-8224506
[TESTBUG] TestDockerMemoryMetrics.java fails with exitValue = 137

WEBREV:
http://cr.openjdk.java.net/~bobv/8224506/webrev.01

This problem occurs when the test is run with a fastdebug build.  The container
that is being created has a memory limit of 20MB which is too small.


NOTE: I will commit each fix individually with incremental changes to ProblemList.txt.


Bob.