[SPARK-3425] do not set MaxPermSize for OpenJDK 1.8

Closes #2387

Author: Matthew Farrellee <matt@redhat.com>

Closes #2301 from mattf/SPARK-3425 and squashes the following commits:

20f3c09 [Matthew Farrellee] [SPARK-3425] do not set MaxPermSize for OpenJDK 1.8