RFR: 8158797: Test java/lang/management/MemoryMXBean/LowMemoryTest.java fails when GC is specified explicitly

[Alexander Kulyakhtin]

Hi,

Could you, please, review this simple, test-only change:

CR: https://bugs.openjdk.java.net/browse/JDK-8158797 "Test java/lang/management/MemoryMXBean/LowMemoryTest.java fails when GC is specified explicitly"
Webrev: http://cr.openjdk.java.net/~akulyakh/8158797/test/java/lang/management/MemoryMXBean/LowMemoryTest.java.udiff.html

In order to verify some expected behavior, the test specifies its own GC options when running.
Currently, if the testing framework runs this test with some other explicitly specifed GC options, then the test fails with "Conflicting collector combinations in option list" message.
We are modifying the test so that it runs only when the framework does not specify any GC options.

Best regards,
Alexander